1) A simple random sample of 36 wait times was collected at a local grocery store checkout line. The mean and standard deviation for the sample were found to be 7.8 min, and 3.4 min, respectively. Estimate the population mean (in other words, get the confidence interval) using a 90% confidence level.

2) Repeat problem (1) using a 99% confidence level.
In problems (1) and (2), which confidence interval is wider? Explain why
there is a difference.

show work please thanks!​