with the graph

Cumulative Abnormal Returns 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. Graph and interpret your results. Do your results support market efficiency? Ross Co. Westerfield, Inc. Jordan Company Market Company Market Company Market Company Date Return Return Date Return Return Date Return Return July 12 -0.2 -0.4 Feb 8 -0.7 -0.9 Oct 1 0.3 0.5 July 13 0.1 0.3 Feb 9 -0.8 -0.9 Oct 2 0.2 July 16 0.6 0.8 Feb 10 0.6 0.4 Oct 3 1.3 July 17 -0.4 -0.2 Feb 11 0.8 1.0 Oct 6 -0.1 -0.5 July 18 - 1.9 1.3 Feb 12 -0.1 0.1 Oct 7 -2.4 -0.5 July 19 -0.8 -0.6 Feb 15 1.3 1.4 Oct 8 0.3 0.3 July 20 -0.9 -1.0 Feb 16 0.7 0.7 Oct 9 -0.5 -0.4 July 23 0.6 0.4 Feb 17 -0.1 0.0 Oct 10 0.1 -0.1 July 24 0.1 0.5 0.4 Oct 13 -0.2 -0.6 0.8 0.9 0.0 Feb 18