Customers per hr.....108 (customers) / 9 (hrs) = 12 customer per hr
Answer:

And replacing:

And the deviation:

And the distribution is given:

Step-by-step explanation:
For this case we have the following info given :

And the deviation would be 
For this case we select a sample size of n = 5 and the distirbution for the sample mean would be:

And replacing:

And the deviation:

And the distribution is given:

I'm pretty sure it's an infinite number of lines
Well Jay has 20 phone numbers.
20j=13r-3x2 im not sure but i hope that helped a little.