Question

If the mean of the following distribution is 24,Find the value 'a

Mark 0-10,10-20,20-30,30-40,40-50

No. 7, a,8,10,5
Of student

Answer 1

hope this helps you ☺☺ ...

Answer is 10..

Answer 2

The value of a is 10.

• We know that mean for grouped data is given by

                $mean = \frac{sum(f_{i} x_{i}) }{sum(f_{i}) }$

• Given,

                   mean = 24

                       $24=\frac{810+15a}{30+a}$

                       24(30+a) = 810 + 15a

                       720 + 24a = 810 + 15a

                       24a - 15a = 810 - 720

                                9a = 90  

                                  a = 90/9

                               ∴ a = 10

             

Please refer attachment for table and calculations.