1. Suppose a fast-food restaurant wishes to estimate average sales volume for a new

menu item. The restaurant has analyzed the sales of the item at a similar outlet and

observed the following results:

__

X = 500 (mean daily sales)

s = 100 (standard deviation of sample)

n = 25 (sample size)

The restaurant manager wants to know into what range the mean daily sales should fall

95 percent of the time. Perform this calculation

2. Suppose you are planning to sample cat owners to determine the average number of

cans of cat food they purchase monthly. The following standards have been set: a

confidence level of 95 percent and an error of less than five units. Past research has

indicated that the standard deviation should be 6 units. What is the required sample size?

3. A researcher expects the population proportion of Cubs fans in Chicago to be 80

percent. The researcher wishes to have an error of less than 5 percent and to be 95

percent confident of an estimate to be made from a mail survey. What sample size is

required?