Using the Excel data attached, please show me the steps on how to complete the following questions.

This data set shows the grades of 40 students in Microeconomics and Macroeconomics collected from universities in the South, collected by an economics education researcher who is interested estimating the average grade in all the Microeconomics and Macroeconomics courses offered.

Questions are based off the excel data.

1. Suppose the population standard deviation of all Microeconomics grade is known and equals to 18. Calculate the sample mean of the 40-student-sample for Microeconomics grade , then compute a 90% confidence interval of the average grade you calculated base on the 40-student-sample, by first writing out the Excel formula/syntax actually used , then calculated the confidence interval

2. Suppose the population standard deviation of all Macroeconomics grade is unknown. Calculate the sample mean and standard deviation of the 40-student sample for Macroeconomics grade , then compute a 95% confidence interval of the average grade you calculated based on the 40-student-sample, by first writing out the Excel formula/syntax actually used, then calculated the confidence interval

Micro 85 78 88 78 70 74 65 81 80 66 70 88 80 91 64 63 76 51 63 60 71 76 69 71 66 65 82 53 75 59 72 82 69 56 79 64 82 65 71 75 Macro 48 79 49 43 56 72 67 84 75 74 100 81 84 75 72 64 75 72 78 86 70 62 96 64 51 91 69 76 59 59 77 52 60 67 70 60 73 92 60 74