The price of a gallon of unleaded gas was $2.86 yesterday. today, the price fell to $2.79 . find the percentage decrease. round your answer to the nearest tenth of a percent

First, solve for the difference between the two prices. That is, $2.79 - $2.86 which is equal to -$0.07. Divide this value by the original price and multiply by 100%. This is shown below,
(-$0.07 / $2.86) x100% = -2.448%
Thus, the percentage decrease is approximately equal to 2.4%.