SAT Math Multiple Choice Question 555: Answer and Explanation
15. A student is drawing the human skeleton to scale for a school assignment. The assignment permits the student to omit all bones under a certain size because they would be too small to draw. The longest bone in the human body is the femur, or thighbone, with an average length of 19.9 inches. The tenth longest bone is the sternum, or breastbone, with an average length of 6.7 inches.
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
Category: Problem Solving and Data Analysis / Rates, Ratios, Proportions, and Percents
Strategic Advice: 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.
Getting to the Answer: