Basic Statistics Flashcards
6 cards from real Civil Service Numerical Reasoning Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Basic Statistics flashcards as text
A data set contains: 3, 3, 7, 7, 7, 9, 9. Which measure of average is 7?
Answer: Mean, median, and mode are all 7
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.
Test scores: 55, 70, 60, 75, 80, 65, 70. What is the mode?
Answer: 70
70 appears twice; all others appear once. The mode is 70.
Five values: 14, 22, 18, 30, 26. What is the mean?
Answer: 22
Sum = 14 + 22 + 18 + 30 + 26 = 110. Mean = 110 ÷ 5 = 22.
A class of 8 students scored: 55, 62, 71, 48, 80, 55, 67, 74. What is the median?
Answer: 64.5
Ordered: 48, 55, 55, 62, 67, 71, 74, 80. Median = (62 + 67) ÷ 2 = 64.5.
What is the range of the values 3.5, 7.2, 1.8, 9.4, 5.6?
Answer: 7.6
Range = 9.4 − 1.8 = 7.6.
Six exam scores: 45, 60, 75, 60, 90, 30. What is the mean?
Answer: 60
Sum = 45 + 60 + 75 + 60 + 90 + 30 = 360. Mean = 360 ÷ 6 = 60.