Short Answer: How does this market analysis come to two seperate conclusions?

Buy HDTV Yes No Buy Exercise Machine Yes No 99 81 54 66 180 120 300 153 147 c({HDTV = Yes} + {Exercise Machine = Yes})=99/180= 55% c({HDTV = No} + {Exercise Machine = Yes})= 54/120=45% Based on that, we should recommend exercise machine to those customers who buy HDTV. But when we look at the two groups of customers in the data (they are the only two groups): Customer Buy Buy Exercise Machine Total Group HDTV Yes No College Students Yes 1 9 10 No 4 30 34 Working Adult Yes 98 72 170 No 50 36 86 For college students: c({HDTV = Yes} + {Exercise Machine = Yes})=1/10 = 10% c{{HDTV = No} + {Exercise Machine = Yes})=4/34=11.8% For working adults: c({HDTV = Yes} + {Exercise Machine = Yes})=98/170= 57.7% c({HDTV = No} + {Exercise Machine = Yes})= 50/86 = 58.1% We should not recommend exercise machine to neither group. How is this possible