Question

Following are the marks obtained by 25 students in economics.
Find out the mean marks by using Direct and Short-cut Method.
`{:("Marks",10,20,30,40,50,60),("Number of Students",5,2,3,8,4,3):}`

Answer 1

Direct Method:

`barX=(sum fX)/(sum f)`
`barX=(880)/25=35.2`
Mean Marks of 25 Students in Economics = 35.2.
Short-cut Method:

`barX=A+(sumfd)/(sumf)`
`=40+(-120)/25=40-(120)/25`
`=40-4.8=35.2`
Thus, Mean Marks = 35.2.