im not sure what i did wrong.

Ross Co, Westerfield, Inc., and Jordan Company announced a new agreement to market their respective products in China on July 18 , February 12, and October 7, respectively. Given the information below. calculate the cumulative abnormal return (CAR) for these stocks as a group. Assume all companies have an expected return equal to the market return. (A negative value should be indicated by a minus sign. Leave no celis blank - be certain to enter " 0 " wherever required. Do not round intermediate calculations. Round your answers to one decimal place.) Answer is complete but not entirely correct