but have hit a road block. I need help with the following:

1. Develop a 98% confidence interval estimate of the population mean number of days to sell for Domestic cars. What is the Margin of error? Interpret your results.
2. Assume the car expert requested estimates of the mean number of days to sell for the Domestic cars with a margin of error of seven days . Using 98% confidence, how large should the sample sizes be for each?
3. Suppose a Domestic car has a list price of $30,000. What is your estimate of the final selling price (based on the percent difference for the sale and list price) and number of days required to sell each of these cars?

Days:

Sample Size: 200

Confidence: 2.33

Margin of Error: 3.01 5.42

Upper Bound 26.74 38.33

Lower Bound 26.74 27.48

Mean 32.905

Standard Deviation 17.86735