Higher November 2017 Paper 4 Q10

OCRHigherCurrent spec5 marksHistograms

10 The histogram summarises a health score for a group of people.

Histogram: health score from 0 to 100 across, frequency density from 0 to 1 up; bars 0 to 30 height 0.2, 30 to 40 height 0.3, 40 to 50 height 0.8, 50 to 70 height 0.5, 70 to 100 height 0.1
(a) Estimate the fraction of the group who had a score of 45 or more. [4]
(b) What assumption did you make in answering part (a)? [1]