Question 1182902
This is a t-test, 2-2way
critical value will be |t| ((df=74)}>1.99, if we use alpha=0.05 p{reject Ho|Ho true}
t=(x bar-mean)/s/sqrt(n)
=(16-15)*sqrt(75)/5.7
=1.519
fail to reject Ho; insufficient evidence that the average time is not 15 years.
p-value =0.13