Question

Compute the mean for the following data:

Marks	No. of students
Less than 10	0
Less than 30	10
Less than 50	25
Less than 70	43
Less than 90	65
Less than 110	87
Less than 130	96
Less than 150	100

mean is 74.80
If true then enter $1$ and if false then enter $0$

Answer 1

We can construct the table shown above with the help of the given data.

We know that, the class-mark or mid-value $x_i=\frac{\text{Upper limit}+\text{lower limit}}{2}$

Also, we know that, mean $\overline{x}=\frac{\sum x_i{f}_i}{\sum f_i}$

From the table, we have, $\sum x_i{f}_i=7480$ and $\sum f_i=100$

$\therefore \overline{x}=\frac{7480}{100}=74.80$

Hence, the given statement is true.