Gas prices decreased in the past month from $3.84 a gallon to $2.31 a gallon. What was the percent change in gas prices? NOTE: Please round your answer the the nearest one hundredth of a percent. For example, if your answer is 0.7856786 or 78.56786%, your answer in Canvas should be 78.57 (do not include a \% sign, but do include a - if your answer is negative).