Answer:
The standard error of the mean is 0.0783.
Step-by-step explanation:
The Central Limit Theorem helps us find the standard error of the mean:
The Central Limit Theorem estabilishes that, for a random variable X, with mean 
and standard deviation 
, a large sample size can be approximated to a normal distribution with mean and standard deviation 
.
The standard deviation of the sample is the same as the standard error of the mean. So
In this problem, we have that:
So
The standard error of the mean is 0.0783.
(-4)^-3 = 
-4^-3 = 
Basically in this situation there is no difference whether parenthesis are used or not.
The second one is correct so its 2
Let's compare the cost of both the centers.
<u>Cost of Center A:</u>
One time charge of $495 in one year.
<u>Cost of Center B:</u>
- Flat $25 dollar sign up fee
- $15 per month, so
dollars a year - $5 per aerobic class, so
dollars a year (given that Billy goes to class once a week) (<em>Note: There are 52 weeks in a year</em>)
Total cost = 
dollars
Hence, Center B would cost 
dollars cheaper.
ANSWER: Least expensive club for Billy to use for a year is Center B
