OCR PURE — Question 10

Exam BoardOCR
ModulePURE
TopicData representation
TypeEstimate mean and standard deviation from histogram

10 The masses of a random sample of 120 boulders in a certain area were recorded. The results are summarized in the histogram.
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  1. Calculate the number of boulders with masses between 60 and 65 kg .
    1. Use midpoints to find estimates of the mean and standard deviation of the masses of the boulders in the sample.
    2. Explain why your answers are only estimates.
  2. Use your answers to part (b)(i) to determine an estimate of the number of outliers, if any, in the distribution.
  3. Give one advantage of using a histogram rather than a pie chart in this context.