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WAEC Mathematics 2015 Question 28

Question 28

Measures of Central Tendency

The table shows the distribution of the scores of some students in a test.
Scores: 0 − 4, 5 − 9, 10 − 14
Frequency: 2, 1, 2
Calculate the mean score.

  1. A.5.6
  2. B.6.2
  3. C.6.6
  4. D.7.0
Show the answer and explanation

Answer: D (7.0)

Explanation

Class midpoints are 2, 7 and 12: mean = (2×2 + 1×7 + 2×12)/5 = 35/5 = 7.0.