Difference between revisions of "2025 AMC 8 Problems/Problem 14"
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| − | The | + | A number <math>N</math> is inserted into the list <math>2</math>, <math>6</math>, <math>7</math>, <math>7</math>, <math>28</math>. The mean is now twice as great as the median. What is <math>N</math>? |
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| + | <math>\textbf{(A)}\ 7\qquad \textbf{(B)}\ 14\qquad \textbf{(C)}\ 20\qquad \textbf{(D)}\ 28\qquad \textbf{(E)}\ 34</math> | ||
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| + | ==Solution== | ||
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| + | The median of the list is <math>7</math>, so the mean of the new list will be <math>7 \cdot 2 = 14</math>. Since there will be <math>6</math> numbers in the new list, the sum of the <math>6</math> numbers will be <math>14 \cdot 6 = 84</math>. Therefore, <math>2+6+7+7+28+N = 84 \rightarrow N = \boxed{\text{(E)\ 34}}</math> | ||
Revision as of 20:53, 29 January 2025
A number
is inserted into the list
,
,
,
,
. The mean is now twice as great as the median. What is
?
Solution
The median of the list is
, so the mean of the new list will be
. Since there will be
numbers in the new list, the sum of the
numbers will be
. Therefore,