Answer:
74.8
Step-by-step explanation:
hope im right!
Answer:
67.02
Step-by-step explanation:
Answer: (17.42, 20.78)
Step-by-step explanation:
As per given , we have
Sample size : n= 9
years
Population standard deviation is not given , so it follows t-distribution.
Sample standard deviation : s= 1.5 years
Confidence level : 99% or 0.99
Significance level : 
Degree of freedom : df= 8 (∵df =n-1)
Critical value : 
The 99% confidence interval for the population mean would be :-


Hence, the 99% confidence interval for the population mean is (17.42, 20.78) .
I think a and y is 2 and 3 because in order to get 5 you have to add
Step-by-step explanation:the answer is c i promise