A random sample of 27 university students is selected and the time spent studying on a typical day, as well as the time spent using social media (Facebook, texting, Twitter, etc.) are recorded (both in minutes). The data are given below:

Social Media: mean = 74; std. dev. = 32
Study Time: mean = 61; std. dev. = 38 Difference (Media - Study):
mean = 13; std. dev. = 20
Assume that all of the appropriate normality assumptions are satisfied.

Question

A random sample of 27 university students is selected and the time spent studying on a typical day, as well as the time spent using social media (Facebook, texting, Twitter, etc.) are recorded (both in minutes). The data are given below:

Social Media: mean = 74;  std. dev. = 32    
Study Time: mean = 61; std. dev. = 38    Difference (Media - Study): 
mean = 13; std. dev. = 20 
Assume that all of the appropriate normality assumptions are satisfied.

anonymous · Answer

We would like to conduct a hypothesis test of H0: μ = 60  vs. Ha: μ not equal to 60 at the 1% level of significance to determine whether there is evidence that the true mean time spent per day on social media for all university students differs from one hour. 
a) What is the value of the test statistic for the appropriate test of significance (rounded to two decimal places)?