This question context is from the textbook Engineering Economic Analysis

Four years ago, Mr.Moneypennypurchased a rare coin for $1,000. Today he sold the coin for $5,000. If the annual inflation rate for the past4 years has been at 5%,state here on Blackboardthe after-tax real percent interest rate (in percent to 2 decimal places, e.g.4.47% or 25.61%) for this investment. Assume the net capital gains tax rate is 15%.