Suppose that two operators A and B work at the job of packing boxes. You have records of the number of boxes packed on the days when A is working, indicated by x0 = 1, when B is working, indicated by X1 = 1, and when A and B ate working together, indicated by x2 = 1:
Estimate the number of boxes packed for A for B and for A and 8 together. Do you think that there is any evidence that when A and B work together they individually pack more boxes or fewer?