21 percent didnot get sick. so 21 percent, thats 21 percent of the total and ten if this will be 79 percent if we just subtract so we should divide 300 by 380, we should get 79 percent as well so one would expect the 21 percent of your total based on the total sample righ over here that 21 percent should be getting sick and 79 percent should not be getting sick. so lets look at this for each of the group. if we assume that 21 percent of this 120 people should have gotten sick, what would have been the expected value right over here? lets just multiply 21 percent times a 120. so lets just multiply that times 120 that gets us to 25.3 people. ill just round it. so the expected ill just write this over here. ill do expected in yellow. so the expected right over here . so if you assume that 21 percent of a group would have gotten sick, you would have expected 25.3 people to get sick in group 1 in herb 1 group and the remainder will not get sick. so lets just subtract. or i can multiply 79 percent times a 120 either one of them will be good. but let me just take 120 - 25.3 and i get 94.7. so you would have expected 94.7 to not get sick. so this is expected again. expected. expected. 