Two independent samples sizes 20 and 30 are randomly selected from two normally distributed populations. Assume that the population variances are unknown but equal. To test the difference between the population means, , the sampling distribution of the sample mean difference, , is:
A) normally distributed
B) t-distributed with 50 degrees of freedom
C) t-distributed with 48 degrees of freedom
D) F-distributed with 19 and 29 degrees of freedom
E) z-distributed with 30 degrees of freedom

Question

Two independent samples sizes 20 and 30 are randomly selected from two normally distributed populations. Assume that the population variances are unknown but equal. To test the difference between the population means,  , the sampling distribution of the sample mean difference,  , is:
A) normally distributed 
B) t-distributed with 50 degrees of freedom 
C) t-distributed with 48 degrees of freedom 
D) F-distributed with 19 and 29 degrees of freedom 
E) z-distributed with 30 degrees of freedom

Quizplus · Accepted Answer

The Answer of Two independent samples sizes 20 and 30 are randomly selected from two normally distributed populations. Assume that the population variances are unknown but equal. To test the difference between the population means,  , the sampling distribution of the sample mean difference,  , is:
A) normally distributed 
B) t-distributed with 50 degrees of freedom 
C) t-distributed with 48 degrees of freedom 
D) F-distributed with 19 and 29 degrees of freedom 
E) z-distributed with 30 degrees of freedom

Two Independent Samples Sizes 20 and 30 Are Randomly Selected