The percentages of voters classed as Liberals in three different election districts are divided as follows: in the first distric
t, 21 percent; in the second district, 45 percent; and in the third district, 75 percent. If a district is selected at random and a voter is selected at random from that district, what is the probability that she will be a Liberal
Assuming that all districts are equally likely to be selected, the probability that a randomly selected voter is a liberal is given by the average of the probability of a voter being a liberal in each district:
The probability that she will be a Liberal is 47%.