The National Bank, like most other large banks, found that using automatic teller machines (ATMs) reduces the cost of routine bank transactions. National installed an ATM in the corporate offices of the Fun Toy Company. The ATM is for the exclusive use of Fun's 610 employees. After several months of operation, a sample of 100 employees revealed the following use of the ATM machine by Fun employees in a month:

Number of Times ATM Used	Frequency
0	20
1	30
2	20
3	5
4	5
5	20

a. What is the estimate of the proportion of employees who do not use the ATM in a month?

b-1. For estimate of the proportion of employees who do not use the ATM in a month, develop a 90% confidence interval.

b-2. Can National be sure that at least 40% of the employees of Fun Toy Company will use the ATM?

c. How many transactions does the average Fun employee make per month?

d. Develop a 90% confidence interval for the mean number of transactions per month.