Suppose the owner in question 65 observed the sales for 60 days and found the average sales to be 115 with a standard deviation of 12. Obtain the 90 % confidence interval for the demand for bagels.

Question 65

A surge in health insurance premiums imposes an additional burden on a business. A random sample of 10 employees indicates that the average cost increase per employee is about $2,345 with a standard deviation of $245.

Assuming a normal distribution for the per-employee increase, construct a 90 % confidence interval for the average increase.