Question

The mean preparation fee H&R Block charged retail customers last year was $183 (the Wall Street Journal, March 7, 2012). Use this price as the population mean and assume the population standard deviation of preparation fees is $50.

1. What is the probability that the mean price for a sample of 30 H&R Block retail

   customers is within $8 of the population mean?

2. What is the probability that the mean price for a sample of 50 H&R Block retail

   customers is within $8 of the population mean?

3. What is the probability that the mean price for a sample of 100 H&R Block retail

   customers is within $8 of the population mean?

4. Which, if any, of the sample sizes in parts (a), (b), and (c) would you recommend to

   have at least a .95 probability that the sample mean is within $8 of the population mean?

i need DISTRIBUTION, MEAN, STANDARD DEVIATION, of x-bar for each question 1-3 and  175<xbar<191 please.

Answer 1

Given that

Population mean ==183

Standard deviation==50

Let price is X

a)

For n=30

We have to find

Now

b)

For n=50

We have to find

Now

C)

n=100

Since we haven't found any of Given n that gives required probability equal to 0.95 so I will not recommended any one of them for 0.95 probability.