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. Date Market Return Company Return July 12 -.2 Westerfield, Inc. Date Market Return Company Return Jordan Company Market Return Company Return Date Feb & -7 Oct 1 .3 .5 .1 .3 Feb 9 -.& -9 Oct 2 .2 .8 .6 .8 Feb 10 .6 .4 Oct 3 .9 1.3 -.4 - 2 Feb 11 .8 1.0 Oct 6 -1 -.5 July 13 July 16 July 17 July 18 July 19 July 20 1.9 1.3 Feb 12 -. .1 Oct 7 -2.4 -.5 ..8 Feb 15 1.3 1.4 Oct 8 .3 .3 -1.0 Feb 16 .7 .7 Oct 9 -.5 July 23 .4 Feb 17 -.1 .0 Oct 10 .1 -.1 July 24 .1 .0 Feb 18 .5 Oct 13 -.6