EmSAT EmSAT Mathematics 3 — Questions and Answers
Question 1: What is the mean of: 4, 8, 6, 10, 2?
- 6 (Correct answer)
- 8
- 5
- 7
Correct answer: 6
Mean = sum ÷ count = (4 + 8 + 6 + 10 + 2) ÷ 5 = 30 ÷ 5 = 6.
Question 2: What is the median of: 3, 7, 1, 9, 5?
- 5 (Correct answer)
- 7
- 3
- 9
Correct answer: 5
Arrange in order: 1, 3, 5, 7, 9. The middle value (3rd of 5) is 5.
Question 3: A bag has 3 red and 7 blue balls. What is the probability of picking a red ball?
- 3/10 (Correct answer)
- 7/10
- 3/7
- 1/3
Correct answer: 3/10
Probability = favorable outcomes ÷ total outcomes = 3 ÷ (3 + 7) = 3/10.
Question 4: What is the standard deviation a measure of?
- Central tendency
- Spread or variability in data (Correct answer)
- The most frequent value
- The middle value
Correct answer: Spread or variability in data
Standard deviation measures the spread or dispersion of data around the mean. A larger standard deviation indicates more variability in the data set.
Question 5: In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?
- 50%
- 68% (Correct answer)
- 95%
- 99.7%
Correct answer: 68%
In a normal distribution, approximately 68% of data falls within one standard deviation of the mean. This is part of the 68-95-99.7 empirical rule.
Question 6: If P(A) = 0.4 and P(B) = 0.3 and A and B are independent, what is P(A and B)?
- 0.7
- 0.1
- 0.12 (Correct answer)
- 0.34
Correct answer: 0.12
For independent events, P(A and B) = P(A) × P(B) = 0.4 × 0.3 = 0.12.
EmSAT EmSAT Mathematics 3
What is the mean of: 4, 8, 6, 10, 2?