Confidence interval for population mean using excel

The present study shows data for delivery times of international  shipments for a logistics company. The company promotes its international   delivery as a service that takes up to 7 days. After receiving multiple   complaints that the delivery time is exceeding 7 days, the quality assurance   team decided to collect data from a random sample to analyze the delivery   times and decide if they should adjust the delivery time the company promises   customers with. We will find the average and standard deviation for the   delivery times for the random sample of shipments. We will find values from   the probability table using excel functions to construct confidence intervals   using different confidence levels. We will use the confidence intervals to   make a conclusion about the population. We will also analyze the width of the   confidence levels. Assume that the distribution of the delivery times is   normal and the sample is randomly selected.    

Use a cell reference or a single formula where appropriate in  order to receive full credit. Do not copy and paste values or type values, as   you will not receive full credit for your answers. For the purpose of grading   the project, you are required to perform the following tasks: