Question
The mean of n items is X . If the first item is increased by 1 , second by 2 and so on, the new mean is :
BITSAT
Mathematics
Statistics
2024
BITSAT 2024 (Memory Based Paper 1)
BITSAT Mathematics Question (2024) — Solution
Options
- A. X + x 2
- B. X +x
- C. X + n +1 2
- D. None of these
Answer
C. X + n +1 2
Step-by-step solution
Let the items be a _1, a _2, . ., a _ n then X = a_1+a_2+ .+a_n n Now, according to the given condition: X = (a_1+1 )+ (a_2+2 )+ + (a_n+n ) n = X + 1+2+3+ +n n = X + n(n+1) 2 n (using sum of n natural nos.) = X + n +1 2 .
Related: Mathematics — Statistics · All PYQ Banks