### Elance Statistics abd Probabilities Test Answers 2015

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### Statistics & Probabilities

#### What is the median of: 5, 10, 15?

10

15

5

9.5

#### The variable X is the value of an uneven dice after one roll. It produced the following probability distribution P(X): P(1) = 0.05 P(2) = 0.28 P(3) = 0.12 P(4) = 0.23 P(5) = ? P(6) = ? What is the probability that X = 5 or X = 6?

0.23

0.42

0.55

0.32

#### How can you convert a variance to a standard deviation?

Square the variance

Take
the square root of the variance

Take the cubed root of the variance

Take the log of the variance

Variance = standard deviation

#### The, "null hypothesis," refers to

that
there is no relationship between two phenomena

That the relationship depends on other factors

That there is a significant relationship between two phenomena

That there is a minor relationship between two phenomena

#### What is the probability of rolling a fair dice and getting an even number?

1/2

1/3

4/6

1/6

#### The number of cars that went through a car wash during the noon hour over each of the past 8 days are the following: 5, 9, 2, 3, 3, 9, 8, 6 What is the range of this data?

8

9

5.6

7

#### A forestry researcher recorded many variables on the trees of a large forest. These variables include the height (in meters), the diameter (in centimeters), the species (pine, oak, etc.), and if the tree had Dutch Elm disease. In this study which variables that were recorded were quantitative?

All of the variables.

Only species and height.

Only
height and diameter.

Only height.

#### Which of the following is a measure of spread?

Median

Mean

Lower Quartile

Range

#### True or false? Qualitative data is strictly numerical.

True

False

#### What is the median of the following 5 numbers? 1, 2, 3, 4, 10

3

1

10

4

#### A normal distribution generally takes the form of _______.

bell
curve

asymptote

None of these

square ruit

#### You flip an unbiased coin 2 times - what is the probability of getting 2 heads?

100%

75%

25%

Cannot determine

50%

#### The Square of the standard deviation is called

Covariance

Variance

Mean

Squared Distribution

#### What is the average of the following 5 numbers? 1, 2, 3, 4, 10

4

1

10

3

#### What is the mode of: 5, 10, 10, 15, 17?

12

11.2

5

10

#### Which of the following is quantitative data:

Test
scores for English class

A prescription written by a physician

A schedule of meetings

A list of song titles

#### A mean calculation is a part of _______ statistics.

Neither of these

non-parametric

parametric

#### What is the value of the middle observation in a ordered set of numbers

Mean

Mode

Median

Central Standard

#### The ______ describes the dispersion of a data set.

mean

median

standard
deviation

None of these

#### You flip an unbiased coin one time - what is the probability of getting tails?

25%

Cannot determine

100%

75%

50%

#### Where would the outliers be if a distribution had a skewness of 0?

Left

Far right

Far left

No
outliers

Right

#### The difference between the highest and lowest scores is called the ______.

mode

range

mean

sample

#### What is the mean of: 5, 10, 15?

11

10

5

1

#### Two coins are tossed, what is the probability that two heads are obtained?

.75

0

.25

.5

.125

#### Let A be a normal distribution with a mean of 3 and B be a normal distribution with a mean of 17. What is the mean of A+B?

14

17

3

20

51

#### What is the skewness of a normal distribution?

4

1

3

2

0

#### The average grade on a midterm exam in a math class is 72. The teacher feels this is too low, so they award 10 extra points to every student in the class. What is the new average grade for the class?

82

62

72

Not enough information.

#### Which of the following is NOT a characteristic of a Normal distribution?

Defined completely by mean and variance

Right
Skewed

Symmetric

Unimodal

#### Discrete and continuous data are both forms of _______ data.

quantitative

incomplete

None of these

qualitative

#### What power is used in the formula for variance?

2

1

3

5

4

#### Your college professor standardizes everyone's test scores. Your standardized score is -1.35. Which of the following statements is true?

Your
test score was below the average.

Your test score had the highest standard deviation.

You scored within one standard deviation of the average test score.

Your test score was above the average.

#### Where would the outliers be if a distribution had a skewness of -50?

Far right

Far
left

Left

Right

No outliers

#### Using previous games to predict the score of a game is an example of ________ statistics.

None of these

descriptive

inferential

incomplete

#### Bob is a high school basketball player, who is a 72% free throw shooter. Bob has missed his first four free throws of the game. What is the probability that Bob makes his fifth free throw?

72%

0%

100%

90%

#### The median grade on a midterm exam in a math class is 72. The teacher feels this is too low, so they award 10 extra points to every student in the class. What is the new median grade for the class?

Not enough information.

72

62

82

#### Where would the outliers be if a distribution had a skewness of +1?

No outliers

Right

Left

Far right

Far left

#### Over the last 360 days of winter in Raleigh, NC (5 winters) we have had snow on 36 days. What is the probability that we will have snow on any random winter day this year?

0.01

0.2

0.1

0.05

#### Which of the following is not a measure of spread?

Upper
Quartile

Range

Standard Deviation

Variance

#### Suppose E is an event in a sample space S with probability .3. What is the probability of the complement of E?

0

1

.3

.7

#### What is true about these 5 numbers? -2, -1, 0, 5, 10

The
mean is larger than the median.

The median and mean are equal to each other.

The median is larger than the mean.

Cannot compare means and medians.

#### Where would the outliers be if a distribution had a skewness of +50?

Left

Right

Far
right

Far left

No outliers

#### You calculate the standard deviation of a data set and find that it is -1.23. From this you can determine which of the following is true?

Every value in the data set is the same.

You
made an arithmetic mistake because standard deviation cannot be negative.

All of the values in the data set are negative.

The mean must be negative.

#### What is the difference between the mean and the median?

Mean is not effected by skewness of the distribution

Median
is not affected by skewness of the distribution

Both are always equal

Mean is always greater than the Median

#### Symbolism: What does the small sigma represent (without any other symbols) in statistics?

Expected Value

Variance

Standard
Deviation

Mean

Skewness

#### What is the skewness of a normal distribution?

2

1

0

4

3

#### How is P(A|B) interpreted?

The probability event A happens given that event B did not
happen

The probability that event A or event B happens

The probability event B happens given that event A has happened

The
probability event A happens given that event B has happened

#### What is true about these 5 numbers? -10, -5, 0, 1, 2

Cannot compare means and medians.

The median and mean are equal to each other.

The
median is larger than the mean.

The mean is larger than the median.

#### Suppose a fair die is tossed twice. What is the probability of rolling two fours?

2/36

2/6/2013

1/6/2013

1/36

#### What is the probability of rolling a fair dice and getting a 1 and flipping a fair coin getting a head?

1/12

1/2

3/12

1/6

#### What is the probability of rolling a fair dice and getting an even number and flipping a fair coin getting a head?

0

0.75

0.25

0.5

#### Which plot is best use to display the relationship between a continuous dependent variable against a continuous independent variable

Box Plot

None of these

Histogram

Scatter
plot

Bar Chart

#### What is expected value?

No such thing

The probability of the next outcome

The maximum loss

All of the other choices, beside "no such thing"

Sum
of all the possible outcomes * the probability of occurrence

#### How do you calculate the Z-Score?

= observation + standard deviation / standard error of the
mean

=
(observation - sample mean) / standard deviation

= observation - standard deviation

= standard error of the mean / standard deviation

= observation + standard deviation

#### _____ are collections of observations.

Data

Populations

Expected values

Random variables

#### If a data set follows a normal distribution, approximately ___% of data falls within 1 standard deviation of the mean.

100%

0%

68%

25%

#### A ______ is a numerical characteristic of a population

None of these

constraint

category

parameter

#### How can you convert a standard deviation to a variance?

Take the log of the standard deviation

Square
the standard deviation

Take the cubed root of the standard deviation

Take the square root of the standard deviation

Variance = standard deviation

#### Experts rank athletic teams 1 through 10. This is an example of ______ data.

discrete

ordinal

categorical

quantative

#### The variable X is the value of an uneven dice after one roll. It produced the following probability distribution P(X): P(1) = 0.05 P(2) = 0.28 P(3) = 0.12 P(4) = 0.23 P(5) = ? P(6) = ? What is the probability that X = 2 or X = 3?

0.45

0.12

0.4

0.28

#### Symbolism: What does the x-bar represent (without any other symbols) in statistics?

Population standard deviation

Sample
mean

Sample standard deviation

Population mean

None of the other options

#### What is the most commonly used statistical measure of spread in a normally-distributed population?

variance

mean

standard
deviation

covariance

z-score

#### The average price of a car in a used car lot is $18,000. These prices are Normally distributed with a standard deviation of $3,000. What is the probability that any random car is below $18,000?

95%

42%

68%

50%

#### Interpret an R-squared coefficient of .6 for a simple linear regression.

We can be 60% certain that there is a causal relationship
between our dependent and independent variables.

There is no interpretation for the R-squared value.

This is an indicator that there must be a moderate positive correlation
between both the dependent and independent variables.

60%
of the variability in our dependent variable can be explained by our
independent variable.

#### Which one of these variables is a continuous random variable?

The number of women taller than 68 inches in a random
sample of 5 women.

The number of tattoos a randomly selected person has.

The
time it takes a randomly selected student to complete an exam.

The number of correct guesses on a multiple choice test.

#### Which of the following is an example of mutually exclusive events?

Being
late to a meeting and being early to the same meeting

Having one product off the assembly line be defective, but another
product on that same assembly line work properly.

Ordering a burger at a fast food restaurant and ordering fries at that
same restaurant

Having it rain on the same day that the sun comes out in the same city

#### What is the mean of a standard normal distribution?

50

100

1

0

0.5

#### In a probability distribution, the second central moment can be another term for which of the following?

Skewness

Average

Variance

Kurtosis

#### When does a Type I error occur?

None of the other choices

You fail to reject the null hypothesis when it is false

All of the other choices

You
reject the null hypothesis when it is true

There is no such term as a "Type I Error"

#### Which of the following statements are true? 1. Categorical variables are the same as qualitative variables. 2. Categorical variables are the same as quantitative variables. 3. Quantitative variables can be continuous variables.

1 only

2 only

1
and 3 only

3 only

#### What is the median of the following 5 numbers? 10, 2, 4, 3, 1

4

10

1

3

#### What is derived from the second moment of distribution?

Skewness

Mean

Pearson's Coefficient of Kurtosis

Variance

Kurtosis

#### Which one of these variables is a binomial random variable?

time it takes a randomly selected student to complete a
multiple choice exam

number of CDs a randomly selected person owns

number
of women taller than 68 inches in a random sample of 5 women

number of textbooks a randomly selected student bought this term

#### The probability of a discrete value in a continuous distribution is equal to __?

0.5

.99

0

-1

1

#### _____ data is an example of nonmetric data.

Quantative

Sample

Parametric

Ordinal

#### Suppose c is a constant number. Calculate var(c).

c^2

c

c^2 - c

c^2+c

0

#### Suppose E and F are mutually exclusive events in a sample space S with probabilities .4 and .3 respectively. What is the probability of their union?

.3

.4

.7

.1

#### What is the formula for the variance of a population?

SUM((( - sample mean)^3) / Number of observations)

SQRT( SUM(((x - sample mean)^3) / Number of observations))

SUM(((observation
- sample mean)^2) / Number of observations)

SUM((observation - sample mean) / Number of observations)

SQRT( SUM)((x - sample mean)^2) / Number of observations))

#### Which of the following would be appropriate for a z-test?

Determining if a small set of pieces of oak firewood burn
longer than pine firewood

Determining
whether the life expectancy of women in a population is statistically different
from that of men

Determining whether regular exercise decreases the number of new heart
disease cases by more than 10% in a year

#### The center line inside a box plot typically represents the _____ in any instance.

Inter-quartile Range

Average of the distribution

Median
of the distribution

2nd Percentile

#### Which of the following is a characteristic of an F-distribution?

Symmetric

Bimodal

No no lower or upper bound

Right
Skewed

#### A bag contains 4 balls (2 red and 2 blue). You pull out one ball at a time without replacement. What is the probability that the fourth ball chosen is a red ball?

1/2

5/12

2/3

9/16

7/12

#### Suppose you have generated this model to predict income: Income = 10 + .5(Years of Education), units are in thousands, ie 10.5 = $10,500. Interpret Beta1.

At zero years of education, income is expected to be
$10,000.

For
every additional year of education, income is expected to increase by $500.

At 5 years of education, income is expected to be $25,000.

For every additional year of education, income is expected to increase
by $10,500.

#### What is the first moment of distribution?

Variance

Skewness

Mean

Standard Deviation

Kurtosis

#### Which of the following statements are true about confidence intervals for means? 1. The center of the confidence interval is always 0. 2. The bigger the confidence interval, the smaller the margin of error. 3. The bigger your sample, the smaller the margin of error.

2 only

1 and 2 only

1 only

3
only

#### If you have a hypothesis test with a significance level of 0.05 and a p-value of 0.01, what is the result of your hypothesis test?

You fail to reject the null hypothesis

Not enough information.

You
reject the null hypothesis

You accept the null hypothesis

#### In hypothesis testing, which of the following statements is always true?

The P-value is computed from the significance level.

The
P-value is a probability.

The P-value is the parameter in the null hypothesis.

The P-value is a test statistic.

#### A manager of a large bank wants to compute the average interest rates across all bonds that the bank invests in. The manager randomly sampled 127 bonds that the bank invests in and calculated the average interest rate over the past year of the sample was 2.47%. What is the parameter of interest in this study?

The 127 bonds used in the calculation.

All bonds that the bank invests in.

The
average interest rate of all bonds that the bank invests in.

2.47%

#### Symbolism: What does the Greek letter mu represent (without any other symbols) in statistics?

Sample mean

Population standard deviation

None of the other options

Sample standard deviation

Population
mean

#### Say 2 events satisfy the following equation: P(A intersect B) = P(A) x P(B). We say that events A and B are __.

Independent

Disjoint

Mutually exclusive

Dependent

#### C(n,r) is equal to...

n!r!

n!/(n-r)!

n!/(r!(n-r)!)

n!/r!

#### Which of the following is A test of normality?

Kolmogrov-Smirnov
Test of Normality

The Standard Test of Normality

Test of Data Normality

Time Series Test of Normality

Marx's Test of Normality

#### P(n,r) is equal to...

n!/(n-r)!

n!/(r!(n-r)!)

n!r!

n!/r!

#### When do you fail to reject the null hypothesis?

P-Value
is > alpha (level of significance)

P-Value is < alpha (level of significance)

#### Which of the following examples involves paired data?

A group of 100 students were randomly assigned to receive
vitamin C (50 students) or a placebo (50 students). The groups were followed
for 2 weeks and the proportions with colds were compared.

A
group of 50 students had their blood pressures measured before and after
watching a movie containing violence. The mean blood pressure before the movie was
compared with the mean pressure after the movie.

A study compared the average number of courses taken by a random sample
of 100 freshmen at a university with the average number of courses taken by a
separate random sample of 100 freshmen at a community college.

None of the above.

#### The preseason odds that the Hartford Whalers will win The Stanley Cup Championship are 1/4, and the odds are the same for the California Golden Seals. What is the probability that BOTH will win the championship?

0

1/16 = 0.0625

7/16 = 0.4375

1/4 = 0.25

1/2 = 0.5

#### What is the cumulative probability at +1 standard deviation, for a random variable with normal distribution?

50.00%

84.13%

34.13%

15.87%

2.28%

#### The median grade on a midterm exam in a math class of 60 students is 85. The teacher gives an additional 5 bonus points to the 3 students who scored the highest on the exam. What is the new median grade for the class?

85

80

90

Not enough information.

#### Find the z-score: mean = 6, standard dev. = 2, observation = 7

1.5

-.5

.5

-1.5

#### P(A)*P(B)=P(A and B) What can you conclude about A and B?

They
are independent.

They are neither independent nor mutually exclusive.

They are mutually exclusive.

They are independent and mutually exclusive.

#### The variance of X is 15. Y=X+5. What is the Variance of Y?

40

Not enough information to determine the Variance of Y.

15

17.5

20

#### What is derived from the third moment of distribution?

Skewness

Mean

Kurtosis

Variance

Standard Deviation

#### A card is drawn randomly from an ordinary deck of playing cards. You win a prize if the card is a heart or the card is an ace. What is the probability that you will win the prize?

17/52

13/52

16/52

1/13

#### Suppose A is always 3. Var(B)=4. What is Var(A+B)?

0

7

13

Not enough information.

4

#### Suppose E and F are events in a sample space S. Suppose further that E has probability .2, F has probability .6, and the intersection of E and F has probability .1. What is the probability of the union of E and F?

.68

.6

.7

.8

#### What power is used in the formula for skewness?

5

4

1

3

2

#### For a random variable X, E[X]=3 and E[X^2]=14. Var[X]=?

11

5

23

0

17

#### What are the characteristics of the f-distribution.

It is normally distributed, and we can perform two-tailed
tests.

It is skewed to the left, and we can perform two-tailed tests.

It is skewed to the right, and we can perform two-tailed tests.

It
is skewed to the right, and we can only use it to perform one-tailed tests.

#### An auto analyst is conducting a satisfaction survey, sampling from a list of 10,000 new car buyers. The list includes 2,500 Ford buyers, 2,500 GM buyers, 2,500 Honda buyers, and 2,500 Toyota buyers. The analyst selects a sample of 400 car buyers, by randomly sampling 100 buyers of each brand. Is this an example of a simple random sample?

Yes, because each buyer in the sample had an equal chance
of being sampled.

Yes, because car buyers of every brand were equally represented in the
sample.

No,
because every possible 400-buyer sample did not have an equal chance of being
chosen.

Yes, because each buyer in the sample was randomly sampled.

#### Suppose E and F are events in a sample space S. Suppose further that E has probability .8 and F has probability .9. What is the largest possible value for the probability of the intersection of E and F?

.2

.9

.7

.8

#### Suppose E and F are mutually exclusive events in a sample space S. Suppose further that E has probability .3 and F has probability .4. What is the probability of the intersection of E and F?

.3

.12

0

.7

#### What is synonymous with the coefficient of determination?

R

Mu

R-Squared

CV

Sigma

#### Which of the following is NOT a commonly used estimator in determining the parameters of an unknown probability density function?

Maximum likelihood

Bayes least squared error

Method of moments

Fourier
transform

Cramér–Rao bound

#### C(n,0) = C(n,n)

False

True

#### Where would the outliers be if a distribution had a skewness of -1?

Down

Right

Up

No outliers

Left

#### What is the expected value of rolling an unbiased die (6 sided)?

1.5

3.5

4.5

2.5

3.0

#### What is the kurtosis of a normal distribution?

3.5

3

4

4.5

2.5

#### Which of the following would be appropriate for ANOVA?

Determining whether an anti-cancer drug increases the
number of patients who survive more than one year

Determining
which of several training programs yields the highest mean performance score on
the exit exam

Determining whether the percentage of female voters is statistically
different than the prior year.

Determining whether the average food delivery time from restaurant A is
shorter than restaurant B

#### What is homoskedastic?

The adjustment factor changes (e.g. epsilon)

The
adjustment factor doesn't change (e.g. epsilon)

I do not know

There is no adjustment factor (e.g. epsilon)

#### What is the probability that two six-sided dice will roll the same number?

1/10

1/36

1/12

None of these

1/6

#### For an airline, many times small cities have limited flights that go into their airports. To get a flight to Columbia, SC you must go through one of three cities: Raleigh, NC, Atlanta, GA, or Charlotte, NC. Two customers from Orlando, FL are trying to get to Columbia, SC with only one stop (one of the three above mentioned cities). Assume that they are equally likely to go through any of the above cities. What is the probability neither of the customers fly through Charlotte, NC?

4/9

2/9

1/3

2/3

#### What is synonymous with the correlation coefficient?

CV

R

R-Squared

Sigma

Mu

#### What is the probability of rolling a seven on two six-sided dice?

1/12

1/7

None of these

1/6

1/10

#### If I tossed a fair coin 3 times, what is the probability of it landing on tails only once?

3/8

1/4

1/8

1/2

#### What is a Type II error?

Rejecting the alternative hypothesis when it is true

Failure
to reject the null hypothesis when it is false

Failure to reject the alternative hypothesis when it is true

Failure to reject the alternative hypothesis when it is false

Rejecting the null hypothesis when it is true

#### How do you calculate the standard error of the mean? (obs. = observations, sqrt = Square Root)

Standard
deviation/ sqrt(number of obs.)

Variance / number of obs.

Sum(obs. - mean)^2 / (number of obs.)

Sqrt(Variance/sqrt(number obs.))

#### Let X follow a Poisson distribution with a rate parameter of 7. What is Var(X)?

1

49

1/7

1/49

7

#### For an airline, many times small cities have limited flights that go into their airports. To get a flight to Columbia, SC you must go through one of three cities: Raleigh, NC, Atlanta, GA, or Charlotte, NC. Two customers from Orlando, FL are trying to get to Columbia, SC with only one stop (one of the three above mentioned cities). Assume that they are equally likely to go through any of the above cities. What is the probability one of the customers fly through Charlotte, NC, while the other does not fly through Charlotte, NC?

4/9

1/3

2/3

2/9

#### In a multiple regression model, what is the best way to test the joint significance of the independent variables?

Comparison of P-values in the model

Z-test

Multiple T-tests

Nested
F-test

#### Suppose E and F are independent events in a sample space S. Suppose further that E has probability .3 and F has probability .4. What is the probability of the intersection of E and F?

.12

.7

1

0

#### Chi-square is used predominantly in _______ statistics.

non-parametric

none of these

descriptive

parametric

#### What does R^2 (R-Squared) calculate?

The squared covariance

The point where the regression crosses the Y axis

The
closeness of a regression to the underlying data

The slope of the regression

The coefficient of variation^2

#### What is the coefficient of variation?

Skewness + Kurtosis

Standard Deviation

Mean^2

Kurtosis minus standard deviation

Normalized
measure of dispersion of a probability distribution

#### Which should you use to analyze a continuous dependent variable against a categorical independent variable?

ANOVA

Logistics Regression

Linear Probability Model

Probit Regression

#### The variance of X is 3. Y=3X. What is the variance of Y?

9

3

1

Not enough information.

27

#### A coin is tossed three times. What is the probability that it lands on heads exactly one time?

0.375

0.125

0.333

0.250

0.500

#### What is another form of expressing beta1 in a simple linear regression? y=dependent variable x=independent variable

cov(xy)/var(y)

var(x)^2/var(x)var(y)

cov(xy)/var(x)

E(x)-E(x)^2

#### What formula is used to determine the probability of a series of outcomes WITH replacement?

Gamma distribution probability

Cumulative probability

Hypergeometric

Gaussian probability

Gaussian or Cumulative probability

#### Which statistic is not a measure of effect size?

Eta squared

F-statistic

partial omega squared

omega squared

R squared

#### A survey was conducted to find the average weight of students living in the dorms or a university. To help improve the accuracy of the study, an equal number of students were randomly selected from each dorm for the sample. This sample is an example of what?

Experiment

Simple
Random Sample

Stratified Random Sample

Block Design

#### Which of the following numbers (measures of kurtosis of a distribution) would represent a platykurtic distribution?

3.5

2

20

3

10

#### Which of the following numbers (measures of kurtosis of a distribution) would represent a leptokurtic distribution?

2

0

4

3

1

#### The variance of X is 5 and the variance of Y is 8. What is the variance of X+Y?

18

15

8

Not
enough information.

13

#### What power is used in the formula for kurtosis?

1

4

3

5

2

#### Which of the assumptions is not one of the assumptions for creating a linear regression model (ie. Gauss-Markov Assumptions)?

There must exist a method of random sampling in order for
our model to have any internal and external validity.

The model estimating the dependent variable must have independent
variables that are linear in parameters.

The distribution of the residuals should have a mean of zero.

The
residuals must have a variance that depends on the values in the explanatory
variable.

#### Which of these linear regression models is quadratic?

Y
= B0 + B1X1 + B2(X1)^2

Y = B0 + B1(X1)^2

Y = B0 + B1(X1*X2)^2

Y = B0 + B1X1 + B2(X2)^2

#### P(X|Y)=.5 P(X)=.2 P(Y)=.4 What is P(X and Y),

.2

.4

.1

.08

.8

#### Suppose E and F are events in a sample space S. Suppose further that E has probability .8 and F has probability .9. What is the smallest possible value for the probability of the intersection of E and F?

.1

.7

.9

.8

#### What is the probability that a coin will land on the same side when flipped twice?

.5

.66

.33

.25

.125

#### Event A and Event B are independent and mutually exclusive. True or False: The probability of A must be 0 or the probability of B must be 0.

False

True

#### A card is drawn randomly from a deck of ordinary playing cards. You win $10 if the card is a spade or an ace. What is the probability that you will win money from playing the game once?

None of these.

13/52

4/13

1/13

17/52

#### Which of the following would be appropriate for a t-test?

Determining which of several medicines has the greatest
effect on cell growth

Determining whether the weight of all male golden eagles in a population
is statistically different from that of female eagles

Determining
if a group of people who slept 4 hours before a test will score lower than a
group of people who slept 8 hours before a test.

Determining whether an anti-cancer drug increases the number of patients
who survive more than one year

#### Suppose E and F are events in a sample space S. Suppose further that E has probability .3, F has probability .4, and the intersection of E and F has probability .2. Find the probability of the intersection of E and (the complement of F).

0

.2

.3

.1

#### P(A|B)=.6 P(A)=.3 P(B)=.4 What is P(B|A)?

.45

.8

.90

.60

.75

#### What is the formula for the Pearsonian Coefficient of Skewness?

3*(population
mean - population mode) / Standard deviation

5*(population mean - population mode) / Variance

3*(population mean - population mode) / Variance

5*(population mean - population mode) / Standard deviation

2*(population mean - population mode) / Variance

#### Suppose X and Y are independent random variables. The variance of X is equal to 16; and the variance of Y is equal to 9. Let Z = X - Y. What is the standard deviation of Z?

25

2.65

7

Not enough information to be able to answer the question.

5

#### What is the probability of drawing an Ace from a deck of cards that includes the two Jokers?

None of these

1/13

1/14

1/54

2/27

#### What is the cumulative probability at -1 standard deviation for a normal distribution?

15.87%

84.13%

2.28%

34.13%

50.00%

#### Which of the following is NOT essential for multiple regression modeling?

There must be no perfect collinearity among independent
variables.

The model must be linear in parameters.

There must be more observations than independent variables to have
enough degrees of freedom to make estimates.

The
sample population must be derived from a normally distributed population.

#### Suppose E and F are events in a sample space S. Suppose further that E has probability .5, F has probability .6, and the intersection of E and F has probability .2. Find the probability of the union of E and (the complement of F).

.3

.6

.8

.5

#### Suppose E and F are independent events in a sample space S. Suppose further that E has probability .3 and F has probability .4. What is the probability of the union of E and F?

.58

.7

.12

.4

#### Is it true that nCr = nC(n-r) ?

yes

no

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