STAT Analysis of Tables and Charts 3 — Questions and Answers
Question 1: A table shows population data: Town A increased from 12,000 to 15,000 over 5 years, while Town B increased from 8,000 to 11,200. Which town had the greater percentage increase?
- Town A, with 25%
- Town B, with 40% (Correct answer)
- Both had the same percentage increase
- Town A, with 40%
Correct answer: Town B, with 40%
Town A: (3,000/12,000)×100 = 25%; Town B: (3,200/8,000)×100 = 40%, so Town B had the greater percentage increase.
Question 2: A line graph has two lines: Line P rises consistently, Line Q falls consistently. They intersect once. What does the intersection point represent?
- The point where P is at its maximum
- The point where Q is at its minimum
- The point where both variables have equal values (Correct answer)
- The point where the rate of change is zero
Correct answer: The point where both variables have equal values
An intersection point on a graph represents where the two lines have the same value at the same x-coordinate.
Question 3: A stacked bar chart shows total revenue of $100K split between Product X and Product Y across three years. In Year 1, X=$60K and Y=$40K; in Year 3, X=$40K and Y=$60K. What changed?
- Total revenue declined
- Product Y became the dominant revenue source (Correct answer)
- Product X grew in absolute terms
- The ratio of X to Y remained constant
Correct answer: Product Y became the dominant revenue source
Product Y's share grew from 40% to 60% of equal total revenue, making it the dominant source in Year 3.
Question 4: A histogram has bars of heights 3, 7, 12, 9, 4 for intervals 0-9, 10-19, 20-29, 30-39, 40-49. The distribution is best described as:
- Uniform
- Skewed right
- Approximately bell-shaped with a peak in the middle (Correct answer)
- Skewed left
Correct answer: Approximately bell-shaped with a peak in the middle
The frequencies rise to a peak in the middle interval (20-29) and fall on both sides, forming an approximately bell-shaped (unimodal) distribution.
Question 5: A table lists monthly expenses: Rent $1,200, Food $400, Transport $150, Entertainment $250, Savings $500. What fraction of total expenses is spent on food and entertainment combined?
- 1/4 (Correct answer)
- 13/50
- 3/10
- 1/5
Correct answer: 1/4
Total = $2,500; Food + Entertainment = $650; 650/2,500 = 13/50, which simplifies to approximately 1/4 (0.26).
Question 6: In a chart, the y-axis scale starts at 500 instead of 0. A bar appears twice as tall as another. What caution should a reader exercise?
- The taller bar represents exactly double the value
- The visual difference is exaggerated; the actual ratio may be much smaller than 2:1 (Correct answer)
- The shorter bar has no significant value
- The chart is invalid and should be ignored
Correct answer: The visual difference is exaggerated; the actual ratio may be much smaller than 2:1
A truncated y-axis makes small differences appear larger visually, so the 2:1 visual ratio does not mean one value is actually double the other.
Question 7: A two-way table shows 200 survey responses. 120 respondents prefer coffee, of whom 80 are female. 80 prefer tea, of whom 30 are female. What percentage of all females prefer coffee?
- 66.7%
- 40%
- 72.7% (Correct answer)
- 57.3%
Correct answer: 72.7%
Total females = 80 + 30 = 110; females who prefer coffee = 80; 80/110 ≈ 72.7%.
STAT Analysis of Tables and Charts 3
A table shows population data: Town A increased from 12,000 to 15,000 over 5 years, while Town B increased from 8,000 to 11,200.
Which town had the greater percentage increase?