MATHEMATICS

JAMB 2007 - Question 7

Mathematics 2007 JAMB Past Questions - Question 7: What is the mean deviation of 3,5,8,11,12 and 21?

What is the mean deviation of 3,5,8,11,12 and 21?
A:
B:
C:
D:
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Correct Answer

A

Explanation

Mean (x) = Ex /n = 3+5+8+11+12+21 / 6 = 10therefore M.D = 7+5+2+1+2+11 =28 /6 = 4.7To find the mean deviation of a set of numbers, we need to calculate the average of the absolute differences between each number and the mean of the set.First, let's calculate the mean of the given set of numbers:Mean = (3 + 5 + 8 + 11 + 12 + 21) / 6    = 60 / 6    = 10Next, we calculate the absolute difference between each number and the mean:|3 - 10| = 7|5 - 10| = 5|8 - 10| = 2|11 - 10| = 1|12 - 10| = 2|21 - 10| = 11Now, we calculate the average of these absolute differences:Mean Deviation = (7 + 5 + 2 + 1 + 2 + 11) / 6              = 28 / 6              = 4.67 (rounded to two decimal places)Therefore, the mean deviation of the given set of numbers is approximately 4.67.