The average of n observation is 50. If one observation of value 75 is added, then the average of all observations is 55. What is the value of n?
Answer & explanation
Correct answer: option 4
50 × n + 75 = 55 (n + 1)
50n + 75 = 55n + 55
5n = 20
n = 4
The average of n observation is 50. If one observation of value 75 is added, then the average of all observations is 55. What is the value of n?
Correct answer: option 4
50 × n + 75 = 55 (n + 1)
50n + 75 = 55n + 55
5n = 20
n = 4