Elance Statistics abd Probabilities Test Answers 2015



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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