Post-UTME Mathematics 2016 Objective — Question 8
Question 8 of 60 from the Post-UTME Screening (Post-UTME) Mathematics 2016 Objective paper, with the correct answer and a full explanation.
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Table: Weight of babies 2,3,4,5 (kg); Frequency 3,4,2,1. The weights of 10 babies were obtained and recorded to the nearest kilogram. Find the variance of the distribution.
- A. 10.50
- B. 7.40
- C. 3.10
- D. 0.89Correct
Explanation
Sum = 2(3)+3(4)+4(2)+5(1) = 6+12+8+5 = 31. Mean = 31/10 = 3.1. Variance = [3(2-3.1)^2+4(3-3.1)^2+2(4-3.1)^2+1(5-3.1)^2]/10 = [3.63+0.04+1.62+3.61]/10 = 8.9/10 = 0.89.
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