Average of ‘n’ observations is 38, average of ‘n’ other observations is 42 and average ofremaining ‘n’ observations is 55. Average of all the observations is :
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 45
Average = Sum of all observation/ number of observation
Sum of ‘n’ observations = 38 × n = 38n
Sum of ‘n’ other observations = 42 × n = 42n
Sum of remaining ‘n’ observations = 55 × n = 55n
Average = (38n + 42n + 55n)/3n
Average = 135n/3n = 45