Answer: 95% confidence interval = 20,000 ± 2.12

( 19228.736 , 20771.263 ) OR ( 19229 , 20771 )
Step-by-step explanation:
Given :
Sample size(n) = 17
Sample mean = 20000
Sample standard deviation = 1,500
5% confidence
∴
= 0.025
Degree of freedom (
) = n-1 = 16
∵ Critical value at ( 0.025 , 16 ) = 2.12
∴ 95% confidence interval = mean ± 


Critical value at 95% confidence interval = 20,000 ± 2.12

( 19228.736 , 20771.263 ) OR ( 19229 , 20771 )