SCENARIO 10-2
A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries.Of primary interest to the researcher was the effect of gender on starting salaries.
The result of the pooled-variance t-test of the mean salaries of the females (Population 1)and males (Population 2)in the sample is given below.

-Referring to Scenario 10-2,the researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than the male MBA graduates.What assumptions were necessary to conduct this hypothesis test?
A)Both populations of salaries (male and female)must have approximate normal distributions.
B)The population variances are approximately equal.
C)The samples were randomly and independently selected.
D)All of the above assumptions were necessary.

Question

SCENARIO 10-2
A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries.Of primary interest to the researcher was the effect of gender on starting salaries.
The result of the pooled-variance t-test of the mean salaries of the females (Population 1)and males (Population 2)in the sample is given below.
 
-Referring to Scenario 10-2,the researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than the male MBA graduates.What assumptions were necessary to conduct this hypothesis test?
A)Both populations of salaries (male and female)must have approximate normal distributions. 
B)The population variances are approximately equal. 
C)The samples were randomly and independently selected. 
D)All of the above assumptions were necessary.

Quizplus · Accepted Answer

All three assumptions (normality, equal population variances, and random/independent sampling) are necessary for a valid hypothesis test using a pooled-variance t-test. Normality of the populations allows for the use of the t-distribution, equal variances assumption ensures accuracy of the test statistic, and random/independent sampling is necessary to make inferences about the larger population of MBA graduates.

SCENARIO 10-2 A Researcher Randomly Sampled 30 Graduates of an MBA Program