The following indicates a random sample of the costs associated with carpet cleaning service in a city. $114 $154 $142 $132 $127 $145 $135 $138 $126 $142 $135 $124 The mean and standard deviation of the sample are 135 and 10.79, respectively. a) Find the confidence interval two-sided 95% confidence level for the population mean, if known to the population standard deviation is 12. b) The confidence interval two-tailed 99% for the average population, with the unknown population standard deviation. Do the same procedure but now assuming that the population standard deviation is not known. c) Find the confidence interval two-sided 95% confidence level for the population mean e) d) The confidence interval two-tailed 99% for the average population, with the unknown population standard deviation. Use Megastat to corroborate results