THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A dependent random sample from two normally distributed populations gives the following results:
n = 20,
= 26.5,s 2 = 3.2
-The confidence interval for the difference between two population means that are normally distributed where the population variances are unknown but assumed to be equal rely on:
A)the Satterthwaite's approximation.
B)the pooled sample variance.
C)the estimated sample variance.
D)the average sample variance.

Question

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A dependent random sample from two normally distributed populations gives the following results:
n = 20,  
= 26.5,s 2 = 3.2
-The confidence interval for the difference between two population means that are normally distributed where the population variances are unknown but assumed to be equal rely on:
A)the Satterthwaite's approximation. 
B)the pooled sample variance. 
C)the estimated sample variance. 
D)the average sample variance.

Quizplus · Accepted Answer

The confidence interval for the difference between two population means that are normally distributed where the population variances are unknown but assumed to be equal relies on the pooled sample variance. This is calculated by taking the weighted average of the sample variances of both populations. Therefore, the correct answer is B.