The data is summarized in the following table. One group (the A/V group) was shown the ad with both audio and video; the second group (video only group) was shown only the video portion of the commercial. The researchers theorized that Solution a) H0:Mean1=Mean2 H1:Mean1 not equal to Mean2 b) Sp^2=(19*1.98^2+19*2.13^2)/(38)=4.22 t0=(3.7-3.3)/2.056*sqrt(1/20+1/20)=0.615 c) for 19df and 0.1 confidence 2.09 we fail to reject null hypothesis.