WGU STatistics Test
1. In a standard 52-card deck, where each card is assigned a numeric value, the mean of the 52 cards is 7.0 with
a standard deviation of 3.742. To test if a representative sample can be attained, the deck is shuffled and 13
cards are randomly drawn, one at a time. Each card is recorded and then returned randomly to the deck before
the next card is drawn. This process of drawing 13 random cards is repeated a total of 20 times, and the mean
and standard deviation of each round is computed.
Which type of sampling is this an example of? Randomization
Multiple comparison Matched
pairs Bootstrap: Bootstrap
2. A study is done to determine if the color of an apple affects the purchase rate by consumers at a grocery
store. Purchase counts for three colors of apples are collected.
Which technique should be used to determine if there is a difference in purchase rate by color?
Rank-based
Randomization t-test
ANOVA: ANOVA
3. A hospital network collects the amount of time it takes doctors to see patients.
Which two techniques are appropriate to compare the mean times of two subsets within this set of doctors?
Choose 2 answers
ANOVA
t-test
Logistic regression
Principal component analysis: ANOVA t-test
, WGU STatistics Test
4. A data analyst needs to determine whether antioxidants in blackberries can reduce age-related cognitive
decline. Twenty-five adults between 65 and 80 are selected to eat blackberries for six months and be retested. The
original scores are compared with the second scores to determine whether there was decline.
What is the appropriate model to test the hypothesis?
z test
ANOVA
Linear regression
Two-sample t-test: Two-sample t-test
5. Which assumption does a data analyst have to make when performing ANOVA on a dataset?
There are just two parameters that are being estimated. The error terms follow a
normal probability distribution. The parameters are additive.
The explanatory variable is continuous.: The error terms follow a normal proba- bility distribution.
6. Which two assumptions are made when the linear regression model is used?
Choose 2 answers
Critical value is based on Fisher's exact test.
Error terms are independent and identically distributed. Variances are not equal.
Parameters ²0, ²1, and Ã2 are constant.: Error terms are independent and identically distributed.
Parameters ² 0, ² 1a, nd à 2a r e constant.
7. Which assumption is required to perform a two-sample t-test?
Equal variance Large
sample size
Small sum of residuals Equal mean: Equal
variance
, WGU STatistics Test
8. Given the following statistical model:
y = 42 - 4.6 b
Match each element of the model with its corresponding term.
Answer options may be used more than once or not at all. Select your answers from the pull-down list.
y Dependent variable Dependent variable 42 Intercept
Intercept
-4.6 Slope Slope
b Independent variable Independent variable: y Dependent variable Dependent variable
42 Intercept Intercept
-4.6 Slope Slope
b Independent variable Independent variable
9. Given the following generalized two-sample t-test equation:
yi ,j = µi + iµ,j
Classify each element in the equation.
Answer options may be used more than once or not at all.
Select your answers from the pull-down list.: yi ,j Observed value Observed value µi Mean response Mean response
iµ,j Error term Error term
10.Given the following linear model:
y i = ²0 + ²1 xi + µi
Classify each element correctly.
Answer options may be used more than once or not at all.
Select your answer from the pull-down list.: y i Response variable Response variable
1. In a standard 52-card deck, where each card is assigned a numeric value, the mean of the 52 cards is 7.0 with
a standard deviation of 3.742. To test if a representative sample can be attained, the deck is shuffled and 13
cards are randomly drawn, one at a time. Each card is recorded and then returned randomly to the deck before
the next card is drawn. This process of drawing 13 random cards is repeated a total of 20 times, and the mean
and standard deviation of each round is computed.
Which type of sampling is this an example of? Randomization
Multiple comparison Matched
pairs Bootstrap: Bootstrap
2. A study is done to determine if the color of an apple affects the purchase rate by consumers at a grocery
store. Purchase counts for three colors of apples are collected.
Which technique should be used to determine if there is a difference in purchase rate by color?
Rank-based
Randomization t-test
ANOVA: ANOVA
3. A hospital network collects the amount of time it takes doctors to see patients.
Which two techniques are appropriate to compare the mean times of two subsets within this set of doctors?
Choose 2 answers
ANOVA
t-test
Logistic regression
Principal component analysis: ANOVA t-test
, WGU STatistics Test
4. A data analyst needs to determine whether antioxidants in blackberries can reduce age-related cognitive
decline. Twenty-five adults between 65 and 80 are selected to eat blackberries for six months and be retested. The
original scores are compared with the second scores to determine whether there was decline.
What is the appropriate model to test the hypothesis?
z test
ANOVA
Linear regression
Two-sample t-test: Two-sample t-test
5. Which assumption does a data analyst have to make when performing ANOVA on a dataset?
There are just two parameters that are being estimated. The error terms follow a
normal probability distribution. The parameters are additive.
The explanatory variable is continuous.: The error terms follow a normal proba- bility distribution.
6. Which two assumptions are made when the linear regression model is used?
Choose 2 answers
Critical value is based on Fisher's exact test.
Error terms are independent and identically distributed. Variances are not equal.
Parameters ²0, ²1, and Ã2 are constant.: Error terms are independent and identically distributed.
Parameters ² 0, ² 1a, nd à 2a r e constant.
7. Which assumption is required to perform a two-sample t-test?
Equal variance Large
sample size
Small sum of residuals Equal mean: Equal
variance
, WGU STatistics Test
8. Given the following statistical model:
y = 42 - 4.6 b
Match each element of the model with its corresponding term.
Answer options may be used more than once or not at all. Select your answers from the pull-down list.
y Dependent variable Dependent variable 42 Intercept
Intercept
-4.6 Slope Slope
b Independent variable Independent variable: y Dependent variable Dependent variable
42 Intercept Intercept
-4.6 Slope Slope
b Independent variable Independent variable
9. Given the following generalized two-sample t-test equation:
yi ,j = µi + iµ,j
Classify each element in the equation.
Answer options may be used more than once or not at all.
Select your answers from the pull-down list.: yi ,j Observed value Observed value µi Mean response Mean response
iµ,j Error term Error term
10.Given the following linear model:
y i = ²0 + ²1 xi + µi
Classify each element correctly.
Answer options may be used more than once or not at all.
Select your answer from the pull-down list.: y i Response variable Response variable
