Answer: (22.41, 25.59)
Step-by-step explanation:
The t-critical value with 17 degrees of freedom for a 95% confidence interval is : 2.11
Sample mean = 24
Standard deviation = 3.2
Standard error of mean = s / √ n
Standard error of mean = 3.2 / √ 18
SE = 3.2/4.2426
Standard error of mean 0.7542
Confidence interval 24-(0.7542)(2.11) = 22.41 and
24+(0.7542)(2.11) =25.59