Help no good at maths

Use the frequency distribution, which shows the number of american voters (in millions) according to age, to find the probability that a voter chosen at random is in the 18 to 20 years old age range. ages frequency 18 to 20 5.9 21 to 24 7.7 25 to 34 20.4 35 to 44 25.1 45 to 64 54.4 65 and over 27.7 the probability that a voter chosen at random is in the 18 to 20 years old age range is nothing. (round to three decimal places as needed.)

Rosy waxes 2/3 of her car with 1/4 bottle of car wax. at this rate, what fraction of the bottle of car wax will rosey use to wax her entire car

How can you tell when x and y are not directly proportional?