In physical therapy there is an average ankle sprain recovery time of 6 weeks. This is a standard time frame given to patients when attending physical therapy twice a week for 6 weeks. From experience, I believe that the time frame is longer than 6 weeks.

Ho: u=6

H1: u>6

xbar=9

alpha=0.05

standard deviation=4

n=15

What is the the z value and the P-value? Do we reject the null hypothesis H0 or not?