wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The average marks in Mathematics for 5 students was found to be 50. Later is was discovered that in case of one student, the marks 48 were misread as 84. The correct average is

A
40.2
No worries! Weā€˜ve got your back. Try BYJUā€˜S free classes today!
B
40.8
No worries! Weā€˜ve got your back. Try BYJUā€˜S free classes today!
C
42.8
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
48.2
No worries! Weā€˜ve got your back. Try BYJUā€˜S free classes today!
Open in App
Solution

The correct option is C 42.8
Average is the sum of the data values divided by the total number of data values.
Given that, average marks of the students with one of students incorrect mark is 50
Number of students is 5
One of the students incorrect mark is 84 and
correct mark is 48
Let the remaining four students marks be x1,x2,x3,x4

Therefore, incorrect average is x1+x2+x3+x4+845=50

x1+x2+x3+x4+84=50×5=250

x1+x2+x3+x4=25084=166 -------(1)

Correct average =x1+x2+x3+x4+485 -------(2)
substituting (1) in (2) we get

Correct average =166+485=2145=42.8

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon