The pie chart shows the distribution of marks scored by 200 pupils in a test.
(a) How many pupils scored : (i) between 41 and 50 marks? ; (ii) above 80 marks ?
(b) What fraction of the pupils scored at most 50 marks?
(c) What is the modal class?
Explanation
(a)(i) The number of pupils who scored between 41 and 50 marks = (frac{90}{360} times 200 = 50)
(ii) The angles for pupils above 60 marks = 54° + 36° + 18° = 108°
(frac{108}{360} times 200 = 60)
(b) The fraction of the pupils who scored at least 50 marks : (frac{54 + 90}{360} = frac{2}{5})
(c) The modal class = 51 – 60; It has the largest angle in the pie- chart.