Question

The mean of the following frequency distribution is 50 find the missing frequencies f1 and f2
Class 0-20 0-40 40-60 60-80 80-100 total

17 f1 32 f2 19 120

Answer 1

Answer:

Step-by-step explanation:

Answer 2

The value of f1 and f2 are 28 and 24.

Solution:

The sum of the frequency is equal to 120, so the sum be 17+f1+32+f2+19 = 120,

which means the sum of f1+f2 = 120 – 68  

f1 + f2 = 52.  

Now for the mean of the frequency we can say that $50=\frac{\sum f_{i} x_{i}}{\Sigma f_{i}}$  that means

The sum of$f_{i} x_{i}$ is equal to $\frac{3480+30 f 1+70 f 2}{120}$

50$=\frac{3480+30 f 1+70 f 2}{120}$

we get the another equation for f1 and f2 i.e. 2520=30f1+70f2

Now equating 2520=30 f1+70 f2 and f1 + f2 = 52.

We get the value of f1 as 28 and f2 as 24.

Therefore, the value of f1 and f2 is equal to 28 and 24 respectively.