Question

The weights (in kg) of 6 girls in a class are 68, 72, 65, 71, 61 and 62. Find the mean weight using the assumed mean method.

• A. 66.5 kg
• B. 67 kg
• C. 68.66 kg
• D. 69.33 kg

Answer 1

The correct option is A 66.5 kg

Choose 65 as the assumed mean i.e. A =65
Number of observations, N =6

$\begin{array}{cc}Weight\left(X\right)& D=X-A\\ 61& -4\\ 62& -3\\ 65& 0\\ 68& 3\\ 71& 6\\ 72& 7\\ & \sum D=9\end{array}$

$Meanweight=A+\frac{\sum D}{N}=65+\frac{9}{6}=66.5kg$