Answer:
See below for answers and explanations
Step-by-step explanation:
<u>Part A</u>
Assuming that conditions have been met for the interval, we use the formula
where
represents the sample mean,
represents the critical value,
represents the sample standard deviation, and
is the sample size.
The critical value of
for an 80% confidence level with degrees of freedom
is equivalent to 
Thus, we can compute the confidence interval:

Therefore, we are 80% confident that the true mean age of all customers is between 30.17 and 35.11 years.
<u>Part B</u>
The margin of error is 
Answer:
Step-by-step explanation:
1+2=3
3/2
1.5 AKA your answer
:)
8*5 = 40
40+2=42
42 over 5 = 42/5
Answer:
this is hard to tell and sorry if I'm wrong but I would say it is only a
Step-by-step explanation:
Aanything in the shaded area is correct if it's not it's wrong