Zooey predicts the movie will be 90 minutes long. if the movie actually is 102 minutes long, what is zooey's percent error? round your answer to the nearest tenth of a percent.

102 - 90 = 12
12 / 102 = 0.1176 = 11.76 rounds to 11.8% <==

%error=100(prediction-actual)/actual

%error=100(90-102)/102

%error≈ -11.8%

Now the negative sign indicates that she underestimated the length of he movie by 11.8%, but technically the percent error is an absolute value so it is just 11.8% error.