PSAT Math Multiple-Choice Practice Question 749

Correct Answer: B

Explanation:

(B) Since the values are selected at random, such a high proportion of values greater than 50 in the selection of 50 random numbers is most surprising. With a larger data set, the values would be expected to average closer to the mean than those in the set of 20 random numbers. Since values are taken between 1 and 100, both sets of data should have a range between 1–100, which explains why choice (A) is incorrect. Choice (C) is incorrect because the ranges of the data sets are similar even though the means of the sets are different. Choice (D) is not correct because portraying these random values in a scatter plot is logical. You can impose a best-fit line on top of the scattered data if you would like to determine a trend.