A health insurance broker records the monthly extended health and dental insurance premiums for 18 non-smoking white-collar clients between the ages of 31 and 40 (measured in $):

61 89 140 132 131 80 111 116 142

109 104 142 146 69 124 100 127 130

a.Calculate the sample mean and standard deviation.

Round to the nearest cent.

x=

s=

b.Construct a 90% confidence interval for the mean monthly insurance premium for all non-smoking white-collar clients between the ages of 31 and 40.

Round to the nearest cent.

_____ < < _____