(1) find the principal amount invested if the amount in a quarterly compounded account with a 3.07% interest rate is $5,993.69 after 66 months.
(2) a bank loans a customer $66,000 for a period of 5 years. the simple interest rate of the loan is 10.5%. what is the total amount that the customer will need to pay the bank over the 5 years

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. the design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 99% confidence interval estimate of μ, the mean duration of game play. 4028 4316 4816 4650 4036 5010 4833 4331 4307