Question

The average of some observations is A, if 1 is added to each observation then find the new average.
1. 2A
2. A - 1
3. A + 1
4. A/2

Answer 1

Correct Answer - Option 3 : A + 1

Given:

Average = A

Concept used:

Average = (Sum of observations)/(Number of observations)

Calculation:

Let the sum of all observation be S and the number of observations be N.

A = S/N

⇒ S = AN

when each of the observation is increased by 1,

New sum = AN + N

New average = (AN + N)/N

⇒ New average = A + 1

∴ The new average is A + 1.