PSAT Math Multiple-Choice Question 788: Answer and Explanation

Question: 788

Assume that the sample in the month portrayed in the table is representative of the coffee shop's sales for an entire year. Based on these assumptions, if a female customer is selected at random, what is the approximate probability that she will purchase a latte?

• A. 0.35
• B. 0.41
• C. 0.46
• D. 0.53

Correct Answer: A

Explanation:

(A) If the sample is representative of the sales for a year, then we would expect the proportion of females who purchased a latte during the year to be the same as the proportion of females who purchased a latte in the sample. In the sample, there were 850 females under 18 and 1,573 females 18 and over for a total of 2,423 females. Also, 325 females under 18 and 530 females 18 and over purchased lattes, for a total of 855 lattes purchased by females in the sample. Therefore, the probability that a randomly selected female would purchase a latte is given by the following fraction:

Choice (A) is the answer.