SAT Math Multiple Choice Question 855: Answer and Explanation
15. A dietician working in the children's ward at a hospital is monitoring the water intakeof all the patients in the ward. The total water intake for each patient is recordedthroughout the day and then averaged over the 24-hour period. The results are recordedin the scatterplot, where each dot represents the average hourly water intake forone child.
A child between the ages of 5 and 8 should consume at least 1 liter of water per day.Based on the data presented in the scatterplot, what percent of the children, ages5-8, in the ward consumed less than the daily-recommended amount? (Note: There are24 hours in one day and approximately 33.814 ounces in 1 liter.)
- A. 35%
- B. 60%
- C. 70%
- D. 85%
Correct Answer: B
Category: Problem Solving and Data Analysis / Scatterplots
Strategic Advice: Always pay careful attention to the units when examining a scatterplot. Here, the daily recommended amount of water is given in liters per day; the data is given in ounces per hour. You'll need to convert the units before you can answer the question. Also make sure you're only including data from ages 5-8.
Getting to the Answer: Start by converting 1 liter per day to ounces per hour. Use the factor-label method to keep your calculations organized:
oz per hour
To find the percent of the children, ages 5-8, in the ward that consumed less than this amount, divide the number of dots that are below 1.41 (including those right on the 1.4 line) for ages 5-8 by the total number of dots for ages 5-8. The result is 14 ÷ 23 ≈ 0.6087, which is closest to 60%. This means (B) is correct.