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) .
The answer is C because 48.9 multiplied by 21.2 is 1036.68
Answer:

Step-by-step explanation:
Given

-- City C
--- City K
Required
Determine the 90% confidence interval
This is calculated using:

Calculating 




For a 90% confidence level, the z-score is 1.65. So:

Calculating the standard deviation 

So:


So:


Answer: 12.5
Step-by-step explanation:
you go on the web and google area of trapezium
0.7+0.65 I’m not sure this is what u were looking for but I hope it helps have a good one