For F, i find x is 11.5 then to calculate the CI

we're given this formula for question it's

then we use that SDx and times it by the tcrit for the confidence interval

buttt

im getting a confidence interval of 4.15, and that seems pretty massive.

my b = 0.232, Sx/y = 0.275, n = 5, Sxx = 250, mean y = 2.482, Y=2.84

is every thing im doing correct?

alsooo im not sure what question e means, could anyone help me understand? do i just make n=6 instead of 5 ?