STAT Quantitative Reasoning in Context 3 — Questions and Answers
Question 1: A table shows that a town's population grew from 45,000 in 2010 to 54,000 in 2020. What was the percentage increase?
- 20% (Correct answer)
- 16.7%
- 25%
- 18%
Correct answer: 20%
(54,000 − 45,000) ÷ 45,000 × 100 = 9,000 ÷ 45,000 × 100 = 20%.
Question 2: A box contains 5 red, 3 blue, and 2 green marbles. If one marble is chosen at random, what is the probability it is NOT red?
- 1/2 (Correct answer)
- 3/5
- 2/5
- 3/10
Correct answer: 1/2
Non-red marbles = 3 + 2 = 5 out of 10 total, giving a probability of 5/10 = 1/2.
Question 3: A worker is paid $18 per hour and works 38 hours in one week. She also receives a $50 bonus. What are her total gross earnings?
- $734 (Correct answer)
- $684
- $750
- $720
Correct answer: $734
18 × 38 = $684, plus the $50 bonus = $734.
Question 4: The median of the data set {12, 15, 9, 22, 18, 7, 14} is:
- 14 (Correct answer)
- 13.5
- 15
- 12
Correct answer: 14
Ordered: 7, 9, 12, 14, 15, 18, 22 — the middle (4th) value is 14.
Question 5: A water tank holds 2,400 liters when full. It is currently 35% full. How many more liters are needed to fill it to 80% capacity?
- 1,080 liters (Correct answer)
- 960 liters
- 1,200 liters
- 840 liters
Correct answer: 1,080 liters
80% of 2,400 = 1,920; 35% of 2,400 = 840; difference = 1,920 − 840 = 1,080 liters.
Question 6: If y varies directly with x and y = 36 when x = 9, what is the value of y when x = 15?
- 60 (Correct answer)
- 54
- 45
- 72
Correct answer: 60
The constant of proportionality k = 36 ÷ 9 = 4; y = 4 × 15 = 60.
Question 7: A graph shows sales rising steeply for three months then leveling off. Which interpretation is most accurate?
- Growth rate slowed but sales are still increasing (Correct answer)
- Sales declined after three months
- Sales grew at a constant rate throughout
- Sales peaked then returned to original levels
Correct answer: Growth rate slowed but sales are still increasing
A leveling-off curve means the rate of increase is decreasing, but the total value is still going up.
STAT Quantitative Reasoning in Context 3
A table shows that a town's population grew from 45,000 in 2010 to 54,000 in 2020.
What was the percentage increase?