Civil Service Numerical Reasoning Test Basic Statistics 3

Question 1

A data set contains: 3, 3, 7, 7, 7, 9, 9. Which measure of average is 7?

Accepted Answer

Mean, median, and mode are all 7

Answer

Mean = (3+3+7+7+7+9+9) ÷ 7 = 45 ÷ 7 ≈ 6.43. Median = 7 (middle value). Mode = 7 (most frequent). So median and mode = 7, not mean.

Question 2

Test scores: 55, 70, 60, 75, 80, 65, 70. What is the mode?

Accepted Answer

70

Answer

70 appears twice; all others appear once. The mode is 70.

Question 3

Five values: 14, 22, 18, 30, 26. What is the mean?

Accepted Answer

22

Answer

Sum = 14 + 22 + 18 + 30 + 26 = 110. Mean = 110 ÷ 5 = 22.

Question 4

A class of 8 students scored: 55, 62, 71, 48, 80, 55, 67, 74. What is the median?

Accepted Answer

64.5

Answer

Ordered: 48, 55, 55, 62, 67, 71, 74, 80. Median = (62 + 67) ÷ 2 = 64.5.

Question 5

What is the range of the values 3.5, 7.2, 1.8, 9.4, 5.6?

Accepted Answer

7.6

Answer

Range = 9.4 − 1.8 = 7.6.

Civil Service Numerical Reasoning Practice Test