Question

The average of a list of 4 numbers is 90.0 . A new list of 4 numbers has the same first 3 numbers as the original list, but the fourth number in the original list is 80 , and the fourth number in the new list is 96 . What is the average of this new list of numbers?

Answer 1

94

Explanation:

Average = sum of numbers / number of items in the set

for the first list, the average is 90 and there are four numbers, the sum of the numbers is 90 x 4 = 360

If the 4th number is 80, the sum of the first 3 numbers = 360 - 80 = 280

so the sum of the first three numbers on the second list is 260. The fourth number is 96. The sum of the numbers = 280 + 96 = 376

Average of the new list = 376 / 4 = 94