Question

Determine the mean of the following distribution: Marks No. of students Below 10 5 Below 20 9 Below 30 17 Below 40 29 Below 50 45 Below 60 60 Below 70 70 Below 80 78 Below 90 83 Below 100 85​

Answer 1

as for hint you've been given cumulative frequency. you need to make table with class intervals having class size equal to 10 , from 10 to 100 for ex

class interval=0-10 its cumulative frequency=5

now you need to find out first normal frequency or fi

then from there you will get total frequency.

after then using class mark or xi like for our example its class mark= (UL +LL)/2= 5

then we will get the fixi

after that its totally depends on your choice from which method you r liking to solve it