Question 1175557
One way test, reject if t0.90, df=19)>1.729
value is t=(71.2-70)/6.9/sqrt(20) note: x bar =71.2 to be more precise.
=1.2*sqrt(20)/6.9=0.7778
fail to reject Ho; p-value=0.22
insufficient evidence to assume the mean is > 70.