The mean of five numbers is 60. Four of the numbers are 50, 60, 40, and 80. What is the fifth number.
Mean is the average of a set of numbers. So add and divide by the number of digits you added. This is little different. Let see here....50+60+40+80=230 / 4 = 57.5 close....hmmmm....Trial and error...230+60=300 / 5 =
Hint: The sum for the five numbers will have to be 300 if the mean is to be 60.
With the first four numbers, the sum is 230. What do you have to add to that to get 300?