Hi We are using the T distribution because a) we do not know the population standard deviation (very common in most cases) b) n < 30 Ho: p = 11 Ha: p < 11 Sample: n = 8, mean = 10.05 and s = 2.4853858567922 α=0.01 critical value(df = 7) = 3.5 t = -.95 /(2.4853858567922/√8) = -1.0811 |-1.0811| < 3.5 Fail to reject Ho. Wish You the Best in your Studies.