Q:8.26 ) Banking fees have received much attention during the recent economic recession as banks look for ways to recover from the crisis. A sample of 43

customers paid an average fee of $12.38 per month on their interest-bearing checking accounts. Assume the population standard deviation is $1.85. Complete parts a and b below.

a. Construct a 90% confidence interval to estimate the average fee for the population.

The 90%

confidence interval has a lower limit of ___

and an upper limit of __

(Round to the nearest cent as needed.)

b. What is the margin of error for this interval?

8.27) The caloric consumption of 30 adults was measured and found to average 2171. Assume the population standard deviation is 270 calories per day. Construct confidence intervals to estimate the mean number of calories consumed per day for the population with the confidence levels shown below.

a. 92 %

b. 94 %

c. 97 %

a. The 94% confidence interval has a lower limit of ____ and an upper limit of _______

(Round to one decimal place asneeded.)

b. The 96 % confidence interval has a lower limit of ____ and an upper limit of _______

(Round to one decimal place asneeded.)

c. The 97 % confidence interval has a lower limit of ____ and an upper limit of _______