When the average price of an item increases from p1 to p2 over a period of n years, the annual rate of inflation r (in decimal form) is given by r=(p2/p1)^(1/n) -1. the average price of a loaf of bread increased from $0.40 in 1970 to $3.20 in 2013. what was the annual rate of inflation r? write your answer in decimal form to the nearest hundredth. r=