A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized below. At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? What is the p-value hypothesis test?
A) Reject the null hypothesis and conclude the means are different.
B) Reject the null hypothesis and conclude the means are the same.
C) Fail to reject the null hypothesis and conclude the means are the same.
D) Fail to reject the null hypothesis and conclude the means are different.

Question

A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized below.  At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? What is the p-value hypothesis test?
A) Reject the null hypothesis and conclude the means are different. 
B) Reject the null hypothesis and conclude the means are the same. 
C) Fail to reject the null hypothesis and conclude the means are the same. 
D) Fail to reject the null hypothesis and conclude the means are different.

Quizplus · Accepted Answer

We need to perform a two-sample t-test for the difference between the means of two independent groups, assuming equal variances. Using the given data, we find that the sample means are x̄1 = 5.5 and x̄2 = 6.5, with a pooled standard deviation of s = 2.345. The t-test statistic is t = -1.699 with 18 degrees of freedom. Using a t-table or calculator, we find the two-tailed p-value to be 0.1046, which is greater than the significance level of 0.01. Therefore, we fail to reject the null hypothesis and conclude that there is not enough evidence to support a difference in mean number of times men and women send a Twitter message in a day.

A Recent Study Focused on the Number of Times Men