JWGU S TATISTICS TEST COMPLETE
DETAILED CASE STUDY
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
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
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
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
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 probability distribution.
, 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 β 0, β 1, and σ 2 are constant. - Error terms are independent and identically distributed.
Parameters β 0, β 1, and σ 2 are constant.
Which assumption is required to perform a two-sample t-test?
Equal variance
Large sample size
Small sum of residuals
Equal mean - Equal variance
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
DETAILED CASE STUDY
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
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
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
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
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 probability distribution.
, 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 β 0, β 1, and σ 2 are constant. - Error terms are independent and identically distributed.
Parameters β 0, β 1, and σ 2 are constant.
Which assumption is required to perform a two-sample t-test?
Equal variance
Large sample size
Small sum of residuals
Equal mean - Equal variance
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
