A sociologist focusing on popular culture and media believes that the average number of hours per week (hrs/week) spent using social media is greater for women than for men. Examining two independent simple random samples of 100 individuals each, the researcher calculates sample standard deviations of 2.3 hrs/week and 2.5 hrs/week for women and men, respectively. If the average number of hrs/week spent using social media for the sample of women is greater than that for the sample of men, what test do you use? (You can use Table 10.3)
a. H1: u > 0, z value
b. H1: u > 0, t value
c. H1: u1 - u2 > 0, t value
d. H1: u1 - u2 > 0, z value