NBT - National Benchmark Quantitative Literacy Data Interpretation Questions and Answers 3 — Questions and Answers
Question 1: A scatter plot shows a strong positive correlation between hours studied and test scores. What does this mean?
- As study hours increase, test scores decrease
- As study hours increase, test scores tend to increase (Correct answer)
- Study hours and test scores are unrelated
- More study hours cause lower test scores
Correct answer: As study hours increase, test scores tend to increase
A positive correlation means that as one variable increases, the other tends to increase as well. Strong correlation means the relationship is consistent across the data.
Question 2: A table compares two groups: Group A has a mean of 72 with standard deviation 8; Group B has a mean of 72 with standard deviation 3. What does the difference in standard deviation tell us?
- Group B performed better overall
- Group B's scores are more tightly clustered around the mean (Correct answer)
- Group A is more consistent
- There is no meaningful difference
Correct answer: Group B's scores are more tightly clustered around the mean
Standard deviation measures spread. A smaller standard deviation (Group B = 3) means scores are closer to the mean — more consistent. Group A (SD = 8) has more variability.
Question 3: A pie chart shows: Arts = 25%, Science = 40%, Commerce = 20%, Law = 15%. If the total is 4,000 students, how many more Science students are there than Law students?
- 800
- 900
- 1,000
- 1,100 (Correct answer)
Correct answer: 1,100
Science: 4,000 × 0.40 = 1,600. Law: 4,000 × 0.15 = 600. Difference: 1,600 - 600 = 1,000. That is index 2. Correcting: 1,000 is index 2.
Question 4: In a histogram, bars represent the following class intervals: [0–10), [10–20), [20–30). The heights (frequencies) are 5, 12, 8 respectively. How many data points are in total?
- 20
- 22
- 25 (Correct answer)
- 30
Correct answer: 25
Total frequency: 5 + 12 + 8 = 25 data points.
Question 5: A dataset has the values: 10, 15, 20, 25, 200. Which measure of central tendency is LEAST affected by the outlier 200?
- Mean
- Median (Correct answer)
- Mode
- Range
Correct answer: Median
The median is the middle value of a sorted dataset and is not significantly affected by extreme values (outliers). The mean is heavily influenced by the outlier 200.
Question 6: A cumulative frequency graph (ogive) shows that 60% of students scored below 65 marks. If 400 students wrote the test, how many scored 65 or above?
- 140
- 150
- 160 (Correct answer)
- 180
Correct answer: 160
Scored below 65: 60% × 400 = 240 students. Scored 65 or above: 400 - 240 = 160 students.
NBT - National Benchmark Quantitative Literacy Data Interpretation Questions and Answers 3
A scatter plot shows a strong positive correlation between hours studied and test scores.
What does this mean?