Question 1174679
Ho: mean >=$80000
Ha: mean < $80000
alpha=0.05 (initially) p{reject Ho|Ho true}
test stat is a t df=11 reject Ho if t < -1.796
mean is $67698.58
s is $19,184.79
calculation t=(x bar-mean)/s/sqrt(n)=-12301.42*sqrt(12)/19184.79
=-2.22
Will reject the hypothesis at both the 5% and the 10% level.
At the 1% level, the critical value is -2.718 and would fail to reject at that significance level.
p-value=0.024

This means that at the 0.05 and 0.10 levels of significance we conclude that the true value of the average outstanding value of the mortgages is < $80000 but not conclude that at the 1% level.