Question 1121207
Ho: average visiting time <=90 minutes
Ha: average visiting time >90 minutes.  Want to reject Ho if there is a true difference.  One way test, since we know which direction the difference will be if significant.
alpha=0.10
One sample t-test 0.90, df=24 since using sd of sample as unbiased estimator of sd of population.
critical value t>1.711
t=(x bar-mean)/s/sqrt(n)=(95.5-90)/15/sqrt (25)
=5.5*5/15=1.83
Can reject Ho at the 10% level and say that the average visiting time is > 90 minutes.