Question

Margot goes to the store to buy curtains without measuring the lenght of her windows. she guesses the windows are 36 inches in length. when she gets home she measures and finds they are 40 inches in length.what is the percent error of her guess.

Answer 1

The percent error is 10%

Explanation:

The lengh of the windows are 40 inches, which is the 100% of the lengh.

What you have to do is to put 40 and 100 in a proportion with her guess, which is 36:

40 / 100 = 36 / x

so you do: (100 x 36) / 40 = 90%

This means that the percent error of her guess is 100% - 90% = 10%