Many people were worried when they found that their photocopiers had been sometimes changing numbers; one photocopier sometimes, although not always, changed 6 into 8. A list of prices was copied on this photocopier. The first five prices on the copy are shown below. $54.80 $60.00 $85.40 $70.80 $78.20 In the original list, the prices had increased by the same amount each time. What was the next price on the original list?