So far I got: I wrote the limits in terms of the mean: 16 - 0.8 = 15.2 and 16 - 0 = 16.

Then I solved for t: t(0.3)= 0.8, t=2.67 which equals 99.3%.

This was a test question I got it wrong but I'm not sure where I went wrong because I tried to follow the book and I continue to get the same answer.