Which relation is also a function? O [(-1,3), (0, 2), (3, -1), (3, 2)}
O {(2,-4), (2,-2), (2, 1), (2,3)}
O {(0, 3), (1, 2), (1, 4), (2, 1)]}
O{(-4,-3), (0, -3), (1, -3), (4, -3)}

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.