Multiple Choice
Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed populations.Assume that the population variances are unknown but equal.In order to test the difference between the population means, ,the sampling distribution of the sample mean difference,
,is:
A) normal.
B) Student-t with 50 degrees of freedom.
C) Student-t with 48 degrees of freedom.
D) None of these choices.
Correct Answer:

Verified
Correct Answer:
Verified
Q128: Two independent samples of sizes 40 and
Q129: The unequal-variances test statistic of <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB4388/.jpg"
Q130: For testing the difference between two population
Q131: The F-test used for testing the difference
Q132: A test is being conducted to test
Q134: A calculus professor wanted to test whether
Q135: The variance of the difference in sample
Q136: When the necessary conditions are met,a two-tail
Q137: A political analyst in Iowa surveys a
Q138: Mass Production Line<br> A quality control