The average of a observations is 40. If we observations of 50 and 60 are added, then the average of all the observatinus will be 41. What is the valme of in?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 28.
Average = 40, new average = 41 after adding 50 and 60
Let original number of observations = n
Total becomes: 40n + 110
New average: (40n + 110)/(n + 2) = 41
Cross-multiply:
40n + 110 = 41n + 82
⇒ 28 = n