A class consists of 9 students with an average age of 40.
When the Instructor arrives the average age of the students and the Instructor is 41.
What is the age of the Instructor?
mean = ∑x/n
41 = [(9*40)+x]/10
Multiply both sides by 10.
410 = 360 + x
Subtract 360.
410 - 360 = x = ?