Finding the mean, word problem.

Question

A list of 5 numbers with a mean of 10. If I remove one of the numbers whose value is 14, what is the mean of the remaining numbers?

Answer 1

The mean is the arithmetic average.  It is the (sum of the values) / (the count of the values).

 

"5 numbers with a mean of 10"   means    (a+b+c+d+e)/5= 10

 

"Remove a 14"   so, let e=14

    (a+b+c+d+14)/5 = 10

 

The mean of the remaining numbers is:    (a+b+c+d)/4

 

  (a+b+c+d+14) = 50

  (a+b+c+d) = 36

 and

  (a+b+c+d)/4 = 36/4 = 9

 

The mean of the remaining 4 numbers is 9.