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PLS HURRY ASAP WILL MARK THE BRAINILEST

The mean (average) of 4 numbers is 88.
What is the fourth number if three of the numbers are 80, 95, and 85?

A. 92
B. 54
C. 75
D. 99
E. None of these

User Igor Hrcek
by
3.5k points

1 Answer

14 votes

Explanation:

Add up the four test scores (80, 95, 85, x) then divide by 4 and set that result equal to 88. The equation you get is (80+95+85+x)/4 = 88. Now solve for x.

(80+95+85+x)/4 = 88

(260+x)/4 = 88

4*(260+x)/4 = 4*88

260+x = 352

x+260 = 352

x+260-260 = 352-260

x = 92

The fourth missing number is 92

User Miquel Adell
by
3.7k points