A distribution of scores has a mean of µ = 50. One new score is added to the distribution and the new mean is found to be µ = 48. From this result, you can conclude that the new score was ____.Group of answer choicesless than 50greater than 50equal to 48between 50 and 52
Question
A distribution of scores has a mean of µ = 50. One new score is added to the distribution and the new mean is found to be µ = 48. From this result, you can conclude that the new score was ____.Group of answer choicesless than 50greater than 50equal to 48between 50 and 52
Solution
To determine the new score added to the distribution, we can use the information given about the means before and after the new score was added.
- Let be the number of scores in the original distribution.
- The original mean is , so the total sum of the original scores is .
- After adding one new score , the new mean becomes .
- The new total number of scores is .
- The new total sum of the scores is .
Using the formula for the mean:
Substitute the given values:
To find , solve the equation step by step:
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Multiply both sides by :
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Distribute 48 on the left side:
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Subtract from both sides:
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Isolate :
Since is a positive integer, is a positive number. Therefore, will be less than 48.
Thus, the new score was less than 48.
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