WGU Statistics Test questions with verified answers
A clinical trial designed to evaluate the efficacy of a new drug to increase HDL
cholesterol is conducted. One hundred patients enroll in the study and are
randomized to receive either a new drug or a placebo. A multiple regression
analysis is used to assess effect modification. Let T = Treatment (1 = new drug, 0 =
placebo), M = male gender (1 = Yes, 0 = No), and TM = the interaction of
treatment and male gender.
Given the following results:
Independent variable Regression coefficient T p-value
Intercept 39.24 65.89 0.0001
T(Treatment) -0.36 -0.43 0.6711
M(Male) -0.18 -0.13 0.8991
TM(Treatment X Male) 6.55 3.37 0.0011
What is the linear regression model?
T = 65.89 - 0.13(M) + 3.37(TM)
HDL = 39.24 - 0.36(T) - 0.18(M) + 6.55(TM)
T = 65.89 - 0.43(T) - 0.13(M) + 3.37(TM)
HDL = 65.89 - 0.43(T) - 0.13(M) + 3.37(TM)
HDL = -0.36(T) - 0.18(M) Ans✓✓✓ HDL = 39.24 - 0.36(T) - 0.18(M) + 6.55(TM)
A company wants to hire employees who are most likely to be successful at selling
the company's products. The data analyst needs to determine if intelligence and
friendliness predict sales performance of current employees. The current
employees are given tests to measure both factors, and their sales performance
data is checked, giving the company three scores for each employee.
,What is the criterion variable for this study?
YOUR
ANSWER CORRECT
ANSWER
Friendliness
Intelligence
Strategy results
Sales performance Ans✓✓✓ Sales performance
A data analyst is doing an analysis using t-tests and gets the following output:
t -stat: 2.8
p-value: .006
Critical value: 1.2
Which conclusion can be drawn?
Accept the null hypothesis.
The critical value is too high.
Reject the null hypothesis.
The two population means are similar. Ans✓✓✓ Reject the null hypothesis
A data analyst is examining the relationship with student drivers between driving
skill and texting. A driving circuit is set up and a group of students are each tested
,twice. The first test is performed while sending and receiving texts and the second
test is recorded without texting. After each of the tests, the number of cones hit
by student drivers is recorded.
What are two appropriate conclusions that should be made?
Choose 2 answers
Dependent variable is continuous.
Independent variable is texting condition.
The distribution is skewed.
A t-test should be used. Ans✓✓✓ Independent variable is texting condition.
A t-test should be used.
A data analyst is performing logistic regression on elements with high
multicollinearity.
What is an assumption of logistic regression that is being violated?
YOUR
ANSWER CORRECT
ANSWER
Normally distributed variables
, Variable independence
High R 2
Categorical data type Ans✓✓✓ Variable independence
A data analyst is studying the relationship between gender and marriage using the
result below:
T = test: Paired two sample for means
Married Gender
Mean 0.48 0.64
Variance 0.26 0.24
Observations 25 25
Pearson correlation 0.220176
Hypothesized mean difference 0
df 24
T stat -1.28103
Confidence level 0.95
P (T<=t) one-tail 0.106213
t critical one-tail 1.710882
P (T<=t) two-tail 0.212425
t critical two-tail 2.063899
Given a confidence level of 95%, what can be concluded?
There is no significant difference of mean between these two groups given the t-
values.
A clinical trial designed to evaluate the efficacy of a new drug to increase HDL
cholesterol is conducted. One hundred patients enroll in the study and are
randomized to receive either a new drug or a placebo. A multiple regression
analysis is used to assess effect modification. Let T = Treatment (1 = new drug, 0 =
placebo), M = male gender (1 = Yes, 0 = No), and TM = the interaction of
treatment and male gender.
Given the following results:
Independent variable Regression coefficient T p-value
Intercept 39.24 65.89 0.0001
T(Treatment) -0.36 -0.43 0.6711
M(Male) -0.18 -0.13 0.8991
TM(Treatment X Male) 6.55 3.37 0.0011
What is the linear regression model?
T = 65.89 - 0.13(M) + 3.37(TM)
HDL = 39.24 - 0.36(T) - 0.18(M) + 6.55(TM)
T = 65.89 - 0.43(T) - 0.13(M) + 3.37(TM)
HDL = 65.89 - 0.43(T) - 0.13(M) + 3.37(TM)
HDL = -0.36(T) - 0.18(M) Ans✓✓✓ HDL = 39.24 - 0.36(T) - 0.18(M) + 6.55(TM)
A company wants to hire employees who are most likely to be successful at selling
the company's products. The data analyst needs to determine if intelligence and
friendliness predict sales performance of current employees. The current
employees are given tests to measure both factors, and their sales performance
data is checked, giving the company three scores for each employee.
,What is the criterion variable for this study?
YOUR
ANSWER CORRECT
ANSWER
Friendliness
Intelligence
Strategy results
Sales performance Ans✓✓✓ Sales performance
A data analyst is doing an analysis using t-tests and gets the following output:
t -stat: 2.8
p-value: .006
Critical value: 1.2
Which conclusion can be drawn?
Accept the null hypothesis.
The critical value is too high.
Reject the null hypothesis.
The two population means are similar. Ans✓✓✓ Reject the null hypothesis
A data analyst is examining the relationship with student drivers between driving
skill and texting. A driving circuit is set up and a group of students are each tested
,twice. The first test is performed while sending and receiving texts and the second
test is recorded without texting. After each of the tests, the number of cones hit
by student drivers is recorded.
What are two appropriate conclusions that should be made?
Choose 2 answers
Dependent variable is continuous.
Independent variable is texting condition.
The distribution is skewed.
A t-test should be used. Ans✓✓✓ Independent variable is texting condition.
A t-test should be used.
A data analyst is performing logistic regression on elements with high
multicollinearity.
What is an assumption of logistic regression that is being violated?
YOUR
ANSWER CORRECT
ANSWER
Normally distributed variables
, Variable independence
High R 2
Categorical data type Ans✓✓✓ Variable independence
A data analyst is studying the relationship between gender and marriage using the
result below:
T = test: Paired two sample for means
Married Gender
Mean 0.48 0.64
Variance 0.26 0.24
Observations 25 25
Pearson correlation 0.220176
Hypothesized mean difference 0
df 24
T stat -1.28103
Confidence level 0.95
P (T<=t) one-tail 0.106213
t critical one-tail 1.710882
P (T<=t) two-tail 0.212425
t critical two-tail 2.063899
Given a confidence level of 95%, what can be concluded?
There is no significant difference of mean between these two groups given the t-
values.
