BMST Data Interpretation and Probability 3 — Questions and Answers
Question 1: A scatter plot shows a strong positive correlation between study hours and test scores. What does this mean?
- As study hours increase, scores tend to increase (Correct answer)
- As study hours increase, scores tend to decrease
- Study hours have no effect on scores
- Scores cause students to study more
Correct answer: As study hours increase, scores tend to increase
A positive correlation means both variables increase together.
Question 2: A deck of 52 cards. What is the probability of drawing a face card (Jack, Queen, King)?
- 3/13 (Correct answer)
- 1/4
- 1/13
- 3/52
Correct answer: 3/13
There are 12 face cards (3 per suit × 4 suits), so P = 12/52 = 3/13.
Question 3: Data set: 5, 8, 8, 12, 15, 8, 20. What is the mode?
- 8 (Correct answer)
- 12
- 5
- 20
Correct answer: 8
The mode is 8 because it appears three times, more than any other value.
Question 4: A histogram shows class intervals 0–10, 10–20, 20–30, 30–40 with frequencies 5, 12, 8, 3. What percentage of data falls in the 10–20 interval?
- 42.86% (Correct answer)
- 30%
- 37.5%
- 40%
Correct answer: 42.86%
Total = 28; 12/28 = 0.4286 ≈ 42.86%.
Question 5: A box plot shows Q1=30, median=45, Q3=60. What is the interquartile range (IQR)?
- 30 (Correct answer)
- 45
- 15
- 60
Correct answer: 30
IQR = Q3 − Q1 = 60 − 30 = 30.
Question 6: If you flip a fair coin 3 times, what is the probability of getting exactly 2 heads?
- 3/8 (Correct answer)
- 1/4
- 1/2
- 1/8
Correct answer: 3/8
Combinations: HHT, HTH, THH = 3 outcomes out of 8 total, so P = 3/8.
Question 7: A table shows defective items per day: Mon=4, Tue=7, Wed=3, Thu=6, Fri=5. What is the mean number of defects per day?
- 5 (Correct answer)
- 4
- 6
- 7
Correct answer: 5
Mean = (4+7+3+6+5)/5 = 25/5 = 5.
BMST Data Interpretation and Probability 3
A scatter plot shows a strong positive correlation between study hours and test scores.
What does this mean?