Digital PSAT Math Practice Question 339: Answer and Explanation

Question: 339

If an amusement park worker measures three riders as being 48 inches, 56 inches, and 40 inches tall and the margin of error of each of the worker's measurements is ±2 inches, what is the possible range of the sum of the riders' actual heights in inches?

• A. 48 ≤ total height ≤ 144
• B. 42 ≤ total height ≤ 150
• C. 138 ≤ total height ≤ 150
• D. 158 ≤ total height ≤ 180

Correct Answer: C

Explanation:

(C) Since there are three separate measurements that are each off by up to 2 units, you can determine the range of possible values by adding all the individual measurements together and then including a range of plus or minus 6:

Choice (C) shows the correct range.