can you make it look like this? Use a T instead of a Z for the critical value for this type of confidence interval 1-alpha=0.90, Alpha=1-0.90=0.10 Alpha/2=0.10/2=0.05 T 0.05 with df: 80=1.664 65 +/- (1.664)(10.2/9) 65+/-1.9 Lower Bound: 65-1.9=63.1 Upper Bound: 65+1.9=66.9