Question 1129971
Ho: time=4.5 years
Ha: time NE 4.5 years
alpha=0.05 P{reject Ho|Ho true}
test statistic is a t df=80  with critical value |t|>1.99
t=(4.75-4.5)/1.2/sqrt(81)
=0.25*9/1.2
=1.875
Fail to reject with p-value = 0.064
Insufficient evidence to reject Ho.