mean marks obtanied by a student in his five subject are 15. in eng. he secures 8 marks, in eco. 12, in maths 18, and in commerce 9. find out the marks he secured in statistics.
Let, the marks obtained in Statistics be y.
We know,
A.M. = Σx/N
Now,
A.M. = 15, N = 5
Σx = 8 + 12 + 18 + 9 + y
⇒15 = (8 + 12 + 18 + 9 + y)/5
⇒ y = 28
Thus, the marks obtained in statistics is 28.