Multiple choice

Weight in Kg's $30$ $32$ $33$ $35$ $37$ No. of students $5$ $9$ $15$ $6$ $3$ The mean for the above observation is

  1. $38$
  2. $33$
  3. $36$
  4. $35$
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B Correct answer
Explanation

The weighted total weight is 30×5 + 32×9 + 33×15 + 35×6 + 37×3 = 1254 kg. The total number of students is 38, so the mean is 1254/38 = 33 kg.

AI explanation

Using the direct method to calculate the weighted arithmetic mean, the mean is the sum of the products of weights and frequencies divided by the total frequency. The total number of students is 5 plus 9 plus 15 plus 6 plus 3, which equals 38. The sum of the products is 150 plus 288 plus 495 plus 210 plus 111, totaling 1254. Dividing this sum by the total frequency gives 1254 divided by 38, which results in a mean of 33.

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