A)

A sample of size 108 from a population having standard deviation = 9 produced a mean of 41. The 99% confidence interval for the population mean (rounded to two decimal places) is:

1) The lower limit is

2) The upper limit is

B)

The mean federal income tax paid last year by a random sample of 30 persons selected from a city was$4295. Suppose the standard deviation of tax paid in this city is

=$965. The 95% confidence interval for the population mean (rounded to two decimal places) is:

1) The lower limit is $

2) The upper limit is $

C)

A random sample of 111 customers, who visited a department store, spent an average of$75 at this store. Suppose the standard deviation of expenditures at this store is

=$20. The 98% confidence interval for the population mean (rounded to two decimal places) is:

1) The lower limit is $

2) The upper limit is $

D)

The mean IQ score of a sample of 69 students selected from a high school is 88. Suppose the standard deviation of IQ's at this school is = 8.3. The 99% confidence interval for the population mean (rounded to two decimal places) is:

1) The lower limit is

2) The upper limit is