Difference between revisions of "2025 AMC 8 Problems/Problem 14"
m (Protected "2025 AMC 8 Problems/Problem 14" ([Edit=Allow only administrators] (expires 17:59, 29 January 2025 (UTC)) [Move=Allow only administrators] (expires 17:59, 29 January 2025 (UTC)))) |
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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,