SOLUTION: the arithmetic mean of five numbers is 60. if the arithmetic mean of the first four numbers is 70, what is the fifth number?
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Question 325577: the arithmetic mean of five numbers is 60. if the arithmetic mean of the first four numbers is 70, what is the fifth number? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! arithmetic mean of five numbers = 60
so the sum of the numbers = 60*5 =300
..
first four numbers mean = 70
sum of these 4 numbers = 280.
so the 5th number is 300-280=20
the fifth number is 20