Civil Service Numerical Reasoning Test Basic Statistics 2

Question 1

The following data shows ages of 7 staff members: 24, 31, 45, 28, 31, 52, 39. What is the mode?

Accepted Answer

31

Answer

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.

Accepted Answer

2.5

Answer

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?

Accepted Answer

£15,000

Answer

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?

Accepted Answer

11

Answer

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?

Accepted Answer

£29,500

Answer

Sum = 177,000. Mean = 177,000 ÷ 6 = £29,500.

Civil Service Numerical Reasoning Practice Test