STAT Data Interpretation from Graphs 2 — Questions and Answers
Question 1: A scatter plot shows student study hours (x-axis) vs. test scores (y-axis). The data points form a cluster rising from lower-left to upper-right. What does this indicate?
- A negative correlation between study hours and scores
- A positive correlation between study hours and scores (Correct answer)
- No relationship between study hours and scores
- A perfect linear relationship with no variation
Correct answer: A positive correlation between study hours and scores
A cluster of points rising from lower-left to upper-right indicates a positive correlation, meaning as study hours increase, test scores tend to increase.
Question 2: A line graph tracks monthly rainfall (mm) over a year. January shows 80mm, April shows 20mm, July shows 5mm, and October shows 60mm. Which season has the least rainfall?
- Spring
- Summer (Correct answer)
- Fall
- Winter
Correct answer: Summer
July falls in summer and has the lowest recorded value of 5mm, making summer the driest season.
Question 3: A pie chart shows the budget allocation of a company: Operations 40%, Marketing 25%, R&D 20%, Admin 15%. If the total budget is $2 million, how much is spent on Marketing?
- $400,000
- $500,000 (Correct answer)
- $300,000
- $250,000
Correct answer: $500,000
25% of $2,000,000 = 0.25 × $2,000,000 = $500,000.
Question 4: A double bar graph compares male and female enrollment in four university departments. The Engineering bars show males at 300 and females at 120. What is the ratio of male to female enrollment in Engineering?
- 2:1
- 5:2 (Correct answer)
- 3:2
- 5:1
Correct answer: 5:2
300:120 simplifies by dividing both by 60, giving 5:2.
Question 5: A cumulative frequency graph (ogive) shows test scores for 200 students. The curve reaches 150 at a score of 70. What percentage of students scored 70 or below?
- 70%
- 75% (Correct answer)
- 80%
- 85%
Correct answer: 75%
150 out of 200 students = 150/200 = 0.75 = 75% scored at or below 70.
Question 6: A histogram of employee salaries has bars at: $20k–$30k (10 employees), $30k–$40k (35 employees), $40k–$50k (40 employees), $50k–$60k (15 employees). Which interval contains the median salary?
- $20k–$30k
- $30k–$40k
- $40k–$50k (Correct answer)
- $50k–$60k
Correct answer: $40k–$50k
Total = 100 employees; the median is the 50th/51st employee. Cumulative counts: 10, 45, 85 — so the 50th employee falls in the $40k–$50k interval.
Question 7: A stacked bar chart shows three product sales over two years. In Year 1, Product A = 200, B = 150, C = 100 (total 450). In Year 2, Product A = 180, B = 200, C = 120 (total 500). Which product showed the greatest percentage increase?
- Product A
- Product B (Correct answer)
- Product C
- Both B and C equally
Correct answer: Product B
Product B increased from 150 to 200, a 33.3% increase — greater than C's 20% and A's negative change.
STAT Data Interpretation from Graphs 2
A scatter plot shows student study hours (x-axis) vs. test scores (y-axis).
The data points form a cluster rising from lower-left to upper-right.
What does this indicate?