Question

A professor wants to show that students can improve their political science grades by reading the newspaper daily. He randomly assigns fifteen students to refrain from reading any newspapers before their first exam. He instructs the other fifteen students to read the newspaper in his office daily for one hour until the exam. He then wants to compare the exam grades of the two groups.

Which statistical test would you use to analyze this data?

State the CV & Decision Rule for the problem.

Assume you analyzed the data. You found t = 1.10. Do you reject the null? (Yes OR No)

Answer 1

a) We should use an independent samples t test for means here. We want to see if the mean score for group reading newspapers is better than the group not reading newspapers before the exam. We are using independent samples test because the two groups are independent.

b) Df = n1+n2-2= 28

Using the generally accepted level of significance of 0.05, critical value is : t0.05, 28= 2.048

So reject H0 if test statistic > critical value ie 2.048 here

c) Since test statistic is 1.1 <critical value, we fail to Reject H0 here. This leads us to the conclusion that there's no difference in the mean scores of the two groups.