I'm having trouble trying to solve #5 (a.) and (b.) please show steps, answers, and a labeled bell-curve for confidence intervals.

Valerie and Diana, of Ev-Ree Dei EymS'Furing Pain Analysis, conducted a survey on the number of hospital visits resulting from playing string instruments such as guitars and cellos. They found, from a nationwide survey, a standard deviation of 0.44 visits. They took a sample of 100 college-aged students and got an average of 2.3 visits. Use this data to answer the following. a. (3pts.) Help them construct a 90% confidence interval estimate for the average number of hospital visits. b. (2pts.) What is the margin of error assuming a level of significance of 5%