Please answer these questions

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 iii): 55 124 128 138 119 85 107 120 89 145 73 141 83 118 153 137 125 89 a. Calculate the sample mean and standard deviation. X2: Round to the nearest cent 8 : Round to the nearest cent b. Construct a 95% confidence interval for the mean monthly insurance premium for all non-smoking white-collar clients between the ages of 31 and 40. .l