Christians estimates that she will spend $250 on new summer clothes. she actually spent $350. what is the percent error? round to the nearest whole percent

The percent error is 40%, given that $250 is the accepted value, which I think it is. 

The equation to solve for percent error is (|accepted value - experimental value|)/accepted value*100= percent error

Substitute numbers, and you get ( |250-350| )/250*100=40%

The second step on the test was the move he was supposed to