First we have to subtract 72 from 604. But we can do it into two steps. Then it makes much easier. 604-72=600+4-70-2=600 +2-70=530+2=532
And now we want to obtain 604 again. But before we calculate it, think what we already did. We subtract 72 from 604 and our result was 532. Now we want back to 604 again, so we have to add 72 to 532. In few steps to do it easier. 532+72= 530 + 2+ 70 + 2= 600 + 4=604
<span>Watching television and reading newspaper are not independent events because P(A|B)=P(A) and P(B|A)=P(B) . I might be wrong so try to look at it a little closer before you take my word for it. </span>
The results of the first die and the second one are independent to each other. The expected value of Z is obtained, therefore, by summing the expected values of both X and Y, because Z = X+Y and X and Y are independent. As a result
