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) .
69.92 when you add them all up and divide it you get 69.92
5^4 equals 625 your welcome
The correct product should have been:
<span>(–4x + 9)2 = </span>(-4x)2 + 2(-4x)(9) + 9^2 = 16x6 - 72x +81
The result is a trinomial and not a binomial nor a difference of two squares.
So, the answer is:
C = Kylie did not understand that this is a perfect square trinomial, and she did not determine the product correctly.