Question

Let m be the midpoint and u be the upper class limit of a class in a continuous frequency distribution. The lower class limit of the class is
(a) 2m − u
(b) 2m + u
(c) m − u
(d) m + u

Answer 1

(a) 2m $-$ u

Given:
Mid value = m
Upper limit = u

We know:
$$\begin{gathered} \frac{\mathrm{Lower}\mathrm{limit}+\mathrm{Upper}\mathrm{limit}}{2}=\mathrm{Mid}\mathrm{value} \\ \Rightarrow \frac{\mathrm{Lower}\mathrm{limit}+u}{2}=m \\ \Rightarrow \mathrm{Lower}\mathrm{limit}+u=2m \\ \Rightarrow \mathrm{Lower}\mathrm{limit}=2m\mathit{-}u \end{gathered}$$