Question

If the mean of the following data is 20.2, find the value of p:

Answer 1

According to the question,

Mean = 20.2

So,

∑f_ix_i/∑f_i = 20.2

So we get,

∑f_ix_i = (10×6)+(15×8)+(20×p)+(25×10+)(30×6)

=610+20p

We also get,

∑f_i=6+8+p+10+6

=30+p

Therefore,

∑f_ix_i/∑f_i=20.2

(610+20p)/30+p=20.2

20.2(30+p) =610+20p

606+20.2p=610+20p

20.2p-20p=610-606

0.2p=4

p=4/0.2

p=20