Question

Find out the mean height from the following data relating to height measurements of 8 persons in centimeters.

$\begin{array}{cccccccc}159& 161& 163& 165& 167& 169& 171& 173\end{array}$

Answer 1

Computation of mean height (Step Deviation Method)

$\begin{array}{ccc}\text{Height}& d=X-A& d^{\prime }=\frac{X-A}{C}=\frac{X-167}{2}\\ \left(X\right)& A=167& C=2\\ 159& -8& -4\\ 161& -6& -3\\ 163& -4& -2\\ 165& -2& -1\\ 167\left(A\right)& 0& 0\\ 169& 2& 1\\ 171& 4& 2\\ 173& 6& 3\\ N=8& & \sum d^{\prime }=-4\end{array}$

Mean Height $\left(\overline{A}\right)=A+\frac{\sum d^{\prime }}{N}\times C=167+\frac{-4}{8}\times 2=166cm$

Mean Height = 166 cm.