costs are rising for all kinds of medical care. the mean monthly rent at assisted living facilities was reported to have increased 27% over the last five years to $3886 (the wall street journal, October 27, 2012. aussume this cost estimate is based on a sample of 128 facilies and , from past studies, it canbe assumed that the population standard deviation is 950$.

a. develop a 90% confidence interval estimate of the population mean monthly rent.

b. develop a 95% confidence interval estimate of the population mean monthly rent.