Question

If the mean of frequency distribution is 34.9, Σf_ix_i = 1000 + a, Σf_i = 30 then the value of a = ______.

विकल्प

• 47

• 48

• 42

• 45

Answer 1

If the mean of frequency distribution is 34.9, Σf_ix_i = 1000 + a, Σf_i = 30 then the value of a = 47.

Explanation:

Mean = `(Σf_i x_i)/(Σf_i)`, 

So, Σf_ix_i = 34.9 × 30 

= 1047 

Given Σf_ix_i = 1000 + a,

We have 1000 + a = 1047 

⇒ a = 47