Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:

Answer: Incomplete question, please edit.
Step-by-step explanation:
Answer:
c
Step-by-step explanation:trust
Answer:
11.6%
Step-by-step explanation:
(new - old)/(old) = 25/215 = .116 = 11.6%
Answer:
2 and 3
Step-by-step explanation:
the x-intercept is 2
the y-intercept is 3