Problema Solution
Using the average for gas 3.98 a gallon 1 year ago, and the average for 6 months ago is 3.56 a gallon, calculate the percent increase or decrease in the price of a gallon of gas over that 6 month time span.
Answer provided by our tutors
1 year ago average gas cost: 3.98 a gallon
6 months ago ago average gas cost: 3.56 a gallon
since 3.56 < 3.98 there is a decrease in the price per gallon
lets calculate the percentage
100*((3.98 - 3.56)/3.98) = 100*21/199 = 100*0.105528 = 10.5528 %
there is a decrease of 10.5528% in the price compared to the price 1 year ago.
indeed
3.98 - 0.105528*3.98 = $3.56