The heights (in cm) of 40 students of a class were recorded

MATHEMATICS · Multi-part · A Level · Mathematics · Data presentation and interpretation · Data presentation and interpretation

Problem

The heights (in cm) of 40 students of a class were recorded. The sum of the heights was found to be 6 690 cm6\,690\,\text{cm} and the sum of the squares of the heights was 1 128 050 cm21\,128\,050\,\text{cm}^2. (i) Find the mean height of the students. (ii) Compute the variance and the standard deviation of the heights, correct to one decimal place. (iii) Comment briefly on the amount of dispersion indicated by the standard deviation in relation to the mean height.

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