You are in a group looking at health care costs of families for your Senior Capstone project. You do a survey of 21 families in your neighborhood and find a mean of $ 535 per month with a standard deviation of $62. Construct a 90% confidence interval for the mean monthly health care costs for families in your neighborhood. How would your results change if you did a 99% interval? What factors would affect your results if you sampled in a different neighborhood than the one you live in?

***Need Equation and solutions ***