Answer
Stem plot of C-13 is appended below. We observe that it is roughly symmetric. Hence a t confidence interval can be used.
Here we have n = 24, x̅ = -2.882, σ = 1.036, df = 23 and Confidence Level = 90%
Using Table C of the book we have t* = 1.729
$σ_{x̅} = \frac{σ}{\sqrt n} = \frac{1.036}{\sqrt 24} = 0.21$
Lower Bound = -2.882 - (1.729)(0.21) = -3.245
Upper Bound = -2.882 + (1.729)(0.21) = -2.52
Work Step by Step
Given above
