1. (a) estimate the volume of the solid that lies below the surface z − xy and above the rectangle r − hsx, yd | 0 < x < 6, 0 < y < 4j use a riemann sum with m − 3, n − 2, and take the sample point to be the upper right corner of each square.

X+ y = k 2x + 3y = k + 1 the point of intersection of the lines has an x-coordinate of a.2k + 1 b.-2k + 1 c.2k - 1

Do social recommendations increase ad effectiveness? a study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. the results are given below. correctly recalled the brandarrival 409153browsing20484b. conduct the hypothesis test, using the 0.025 level of significance. what is the value of the test statistic? χ2stat=what is the p-value? p-value=is this value significant atα=0.025?

2x minus y equals 6, x plus y equals negative 3