Okay. To find the percent discount of the sale price, we can write and solve a proportion. You set up the proportion like this:
change/original = x/100
Change is the amount between both numbers and the original is the previous amount. In this case, we are solving for "x", which is the percent discount. 170 - 143.20 is 26.8. Now, let's plug in the values: 26.8/170 = x/100. Cross multiply the values diagonally to get 2,680 = 170x. Divide each side by 170 to isolate the "x". 2,680/170 is 15.76470588254 or 16% when rounded to the nearest whole number. x ≈ 16%. The percent discount is approx. 16%.