Question 1001739
This is a t-distribution, so 95% CI for t(df=14) is 
496 +/- 2.145(108/sqrt(15); mean +/- t-value *SE, where SE= s/sqrt(n)
the SE here is 27.89.  Without rounding until the end, the CI=496+/-59.81
(436.19, 555.81).