(a) Marks Class boundary Freq Cum freq 0 - 9 0 - 9.5 4 4 10 - 19 9.5 - 19.5 5 9 20 - 29 19.5 - 29.5 6 15 30 - 39 29.5 - 39.5 12 27 40 - 49 39.5 - 49.5 8 35 50 - 59 49.5 - 59.5 5 40 (b) Mode = 35.5 (c) Median = \(L_{1} + \frac{(\frac{N}{2} - \sum f_{p}) \times c}{f_{m}}\) where \(L_{1}\) = lower class boundary of median class = 29.5 \(N = \sum f = 40\) ; \(\sum f_{p}\) = cumulative frequency before median class = 15. \(f_{m}\) = frequency of median class = 12, c = class interval = 10. Median = \(29.5 + \frac{(\frac{40}{2} - 15) \times 10}{12}\) = \(29.5 + \frac{(20 - 15) \times 10}{12}\) = \(29.5 + 4.17 = 33.67\)