Two thousand tickets are sold for P20.00 each. One ticket will win P10,000.00, two tickets will win P5,000.00 each and three tickets will win P1,000.00 each. Let X denotes the net gain from the purchase of a randomly selected ticket. a. Construct the probability distribution of X.

b. Find the expected value of X (mean) and variance, then interpret.

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?