Question

From the following data, calculate the weighted mean.

Marks	62	77	65	62	57
Weights	2	1	2	3	4

Answer 1

Marks (X)	Weight (W)	WX
62 77 65 62 57	2 1 2 3 4	124 77 130 186 228
	$\mathit{\Sigma }\mathit{W}$=12	$\mathit{\Sigma }\mathit{W}\mathit{X}$=745

${\overline{X}}_W=\frac{\Sigma WX}{\Sigma W}$

$$\begin{gathered} {\overline{\mathrm{X}}}_w=\frac{745}{12} \\ \Rightarrow {\overline{\mathrm{X}}}_w=62.08 \end{gathered}$$

Hence, the weighted mean is 62.08 marks