Question

& If we wanted to determine whether the mean $ K time all for high school runners is less than 28 minutes, what would our hypotheses be? (Don't forget to define the parameter of interest) h. Would you have any reservations about doing a t-test with the above data? Why or why not?

Answer 1

g) Let µ be the population mean time for all high school runners for 5k  

Claim : Mean time for all high school runner is less than 28 minutes

он
: µ = 28 vs
HO
: µ < 28

h) if population standard deviation σ is known then we use z test, otherwise we can use t test.

In the above example, we are not given any information about the population standard deviation σ, therefore we do not have any reservations about doing a t test.