Question

Find the values of p, q, r and s in the given cumulative frequency distribution.

$\begin{array}{ccc}x& \text{frequency}& \text{Cumulative frequency}\\ 10& 3& p\\ 15& 10& q\\ 20& 25& r\\ 25& 7& s\\ 30& 5& 50\end{array}$

• A. p = 0, q = 10, r = 35, s = 42
• B. p = 3, q = 13, r = 28, s = 35
• C. p = 3, q = 13, r = 35, s = 42
• D. p = 3, q = 13, r = 38, s = 45

Answer 1

The correct option is D p = 3, q = 13, r = 38, s = 45

As cumulative frequency is the sum of all previous frequencies up to the current point,

$\begin{array}{ccc}x& \text{frequency}& \text{Cumulative frequency}\\ 10& 3& p=3\\ 15& 10& q=10+3=13\\ 20& 25& r=13+25=38\\ 25& 7& s=38+7=45\\ 30& 5& 45+5=50\end{array}$