PSAT Math Multiple-Choice Question 207: Answer and Explanation

Question: 207

The student draws the femur, but then realizes she drew it too long, at 3.5 inches. She doesn't want to erase and start over, so she decides she will adjust the scale factor to match her current drawing instead. Based on the new scale factor, about how long in inches should she draw the sternum?

• A. 0.8
• B. 1
• C. 1.2
• D. 1.5

Correct Answer: C

Explanation:

C

Difficulty: Easy

Category: Problem Solving and Data Analysis/Rates, Ratios, Proportions, and Percents

Getting to the Answer: Don't make this question harder than it actually is. You don't need to find the new scale factor. Instead, use the length that the student drew the femur and the actual length to set up and solve a new proportion:

Choice (C) is correct.