Civil Service Numerical Reasoning Test Basic Statistics 2 — Questions and Answers
Question 1: The following data shows ages of 7 staff members: 24, 31, 45, 28, 31, 52, 39. What is the mode?
- 31 (Correct answer)
- 28
- 45
- 24
Correct answer: 31
31 appears twice; all other values appear once. The mode is 31.
Question 2: Find the mean of: 0.5, 1.5, 2.5, 3.5, 4.5.
- 2.5 (Correct answer)
- 2
- 3
- 1.5
Correct answer: 2.5
Sum = 0.5 + 1.5 + 2.5 + 3.5 + 4.5 = 12.5. Mean = 12.5 ÷ 5 = 2.5.
Question 3: Five monthly sales figures are: £12,000; £15,000; £9,000; £18,000; £21,000. What is the median?
- £15,000 (Correct answer)
- £12,000
- £18,000
- £9,000
Correct answer: £15,000
Ordered: £9,000; £12,000; £15,000; £18,000; £21,000. Middle value = £15,000.
Question 4: A dataset has values: 8, 12, 15, 7, 10, 18, 12, 9. What is the range?
- 11 (Correct answer)
- 10
- 12
- 9
Correct answer: 11
Range = highest − lowest = 18 − 7 = 11.
Question 5: Six employees earn: £22,000; £25,000; £28,000; £31,000; £34,000; £37,000. What is the mean salary?
- £29,500 (Correct answer)
- £28,000
- £30,000
- £31,000
Correct answer: £29,500
Sum = 177,000. Mean = 177,000 ÷ 6 = £29,500.
Question 6: Find the median of: 5, 5, 5, 10, 15, 20, 20.
- 10 (Correct answer)
- 5
- 15
- 7.5
Correct answer: 10
Ordered: 5, 5, 5, 10, 15, 20, 20. The middle (4th of 7) value is 10.
Civil Service Numerical Reasoning Test Basic Statistics 2
The following data shows ages of 7 staff members: 24, 31, 45, 28, 31, 52, 39.
What is the mode?