Question
Mathematics Question on Mean Deviation
Let the mean and variance of the frequency distributionxi | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 |
---|---|---|---|---|---|---|---|---|
fi | 4 | 4 | α | 15 | 8 | β | 4 | 5 |
are 9 and 15.08 respectively, then the value of α2+β2-αβ is ____. |
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Answer
The correct answer is: 25
Let the mean and variance of the frequency distributionxi | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 |
---|---|---|---|---|---|---|---|---|
fi | 4 | 4 | α | 15 | 8 | β | 4 | 5 |
are 9 and 15.08 respectively, then the value of α2+β2-αβ is ____. |
\
The correct answer is: 25