SOLUTION: the mean of a set of numbers is 120. if one number is increased by 300, the mean increases to 135. how many numbers are in the set?
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Question 178127: the mean of a set of numbers is 120. if one number is increased by 300, the mean increases to 135. how many numbers are in the set? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! the mean of a set of numbers is 120. if one number is increased by 300, the mean increases to 135. how many numbers are in the set?
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Let the number of numbers be "n".
Then (sum of numbers)/n = 120
or old sum = 120n
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If one of the numbers is increased by 300 the new sum = (old sum + 300)
Then (new sum)/n = 135
or new sum = 135n = old sum + 300 = 120n + 300
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Equation:
135n = 120n + 300
15n = 300
n = 20
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Cheers,
Stan H.
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