1. Sampling Distribution show all your work for full point.

A bank in a small town has 10,000 customers. A national survey on the banking habits of people in U.S. shows that 80% of the people with income higher than 50,000 dollars have both savings and checking accounts and also shows that the average number of banking operations that a person aged 18 and over performs per week is 5. The manager of the bank decides to do a survey among the customers of his bank and takes a simple random sample of 200 customers aged 18 and over. In the sample, the average number of banking transactions per week is 8 with standard deviation equal to 10.

a) The average number of times a customer carries out banking transactions per week is _________ give or take ________ or so. Show how you computed your answers.

b) Give a 90% confidence interval for the average number of banking operations per week for the town residents aged 18 and over. Show your working.

c) Is the apparent difference in banking habits between the nation and the customers of the bank real or just due to chance? Explain

d) A 95% confidence interval gives a range of values for the _______which are plausible according to the observed data. Fill in the blanks.

(Possible answer: (A) Population average, (B) Sample average).

e) The sample standard deviation measures how far _______ is from sample average.

The standard deviation for the sample average measures how far __________is           from the population average - for typical   __________. 

To fill in the blanks, choose among: (A) number of bank operations, (B) average number of operations, (C) samples, (D) customers aged 18 and over, (E) bank, (F) person with high income.