Question

find the mean immediately​

Answer 1

Answer: 64.55 is the mean

Step-by-step explanation:

The classes are-

0-10,10-20,20-30,30-40,40-50,50-60,60-70,70-80,80-90,90-100

The class mark of above classes are-

5,15,25,35,45,55,65,75,85,95

By adding the frequency , we get

700

Multiply class mark with frequency

5*12,15*22,25*35,35*50,45*70,55*86,65*97,75*104,85*109,95*115

By multipy this and adding their answer , we get 45190

Now ,

Divide 45190 by 700

we get the mean

i.e. 64.55