A homeowner spends $3,000 to insulate his home. His energy bills will drop by an average of $85 each month. What is the payback time of this investment? Round, if necessary, to the nearest 0.1 year. 

A homeowner spends $3,000 to insulate his home. His energy bills will drop by an average of $85 each month. What is the payback time of this investment? Round, if necessary, to the nearest 0.1 year.

$5000 is deposited into a well-run bond fund, which pays an annual yield of 4.5%. The average inflation rate is 2.8%.

a) What is the (nominal) value after 9 years? Round down to the nearest penny.

b) How much real interest has been earned after 9 years? Round to the nearest dollar.