The following table gives the marks scored by students in an exam.
MarksNo. of studentsAbove 080Above 1077Above 2072Above 3065Above 4055Above 5043Above 6023Above 7016 Above 8010Above 908Above 1000
Find the mean for the following data using assumed mean method. [4 MARKS]
Table: 2 Marks
Application: 2 Marks
Let the assumed mean be 45
Classintervalxifidifidi0−1053−40−12010−20155−30−15020−30257−20−14030−403510−10−10040−5045120050−6055201020060−706572014070−807563018080−90852408090−10095850400
∑fi=80
∑fidi=490
Mean
=45+49080
=45+6.125
=51.25