The median of 100 observations grouped in classes of equal width is 25. If the median class interval is 20-30 and the number of observations less than 20 is 45, then the frequency of median class is

Options

A. 20
B. 12
C. 10
D. 15

Answer

C

Explanation

We have,
`N=100, F=45, l =20, h=10" and Median "=25`
Let f be the frequency of the meidan class.
Then,
Median `=l+((N)/(2)-F)/(f) xx h`
`rArr 25=20+(50-45)/(f) xx 10`
` rArr 5=(50)/(f) rArr f=10`