Statistics and probabilities

Question

Baruch professors claim that they spend more time re-enacting scenes from Game of Thrones than other professors. Thirty Baruch professors who were randomly selected had a mean time of re-enactment of 95 minutes with a standard deviation of 20 minutes. As reported in the "Chronicle of Higher Education", the national average of professor GoT re-enactment was 83 minutes. Do Baruch professors spend more time re-enacting?

What's your obtained value?

Answer 1

Ho: mu = 83

Ho: mu > 83

degrees of freedom = 30 -1 = 29, critical t-value at alpha = 0.05 is 1.699

t = (95 - 83) / (20/sqrt(30)) = 3.29

since t > t critical , reject Ho.