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?

average of new list is 94

Step-by-step explanation:

Average = sum of numbers/ total number of numbers

Let the original list contain x,y,z and 80

Average = 90

Numbers = 4

Average of original list

=(x+y+z+80)/4=90

x+y+z+80= 360

x+y+z=280

Let (x+y+z) = b

b = 280

The new list has 4 numbers and the same first 3 numbers as the original list, but the the fourth number in the new list is 96.

That means the sum of the first 3 numbers, (x+y+z) which equals b in the original list is same as the sum of the first 3 numbers in the new list

Let average of the new list be a

Average of new list

=(b +96 )/4 =a

b +96 = 4a

b = 4a-96

Since b in original list = b in new list

4a-96 = 280

4a = 280+96=376

a = 376/4 =94

i got 10.28 but that rounds up to 10.3