Question

The histogram below represents the scores obtained by 25 students in a Mathematics mental test. Use the data to: [4 MARKS]
i) frame a frequency distribution table.
ii) to calculate mean
iii) to determine the modal class

Answer 1

Part (i) : 1 Mark
Part (ii) : 2 Marks
Part (ii) : 1 Mark
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i) $\begin{array}{cc}Marks& No.ofstudents\\ 0-10& 2\\ 10-20& 5\\ 20-30& 8\\ 30-40& 4\\ 40-50& 6\end{array}$

ii) $\begin{array}{ccccc}Marks& f& x& u=\frac{x-25}{10}& fu\\ 0-10& 2& 5& -2& -4\\ 10-20& 5& 15& -1& -5\\ 20-30& 8& 25=A& 0& 0\\ 30-40& 4& 35& 1& 4\\ 40-50& 6& 45& 2& 12\\ Total& 25& & & 7\end{array}$
$\therefore \overline{x}=A+\frac{\sum fu}{\sum f}\times i=25+\frac{7}{\text{/}{25}_5}\times \text{/}{10}^2$

iii) Modal clas = 20 - 30