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Standard X

Mathematics

Step-Deviation Method of Finding Mean

A class consi...

Question

A class consist of $50$ students out of which $30$ are girls. The mean marks scored by girls in a test is $73$ (out of $100$ ) and and that of boys is $7171$ . Determine the mean score of the whole class.

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Solution

Mean score of $30$ girls $= 73$
total score $= 73 \times 30$
Mean score of $20$ boys $= 71$
total score $= 71 \times 20$
Mean score of clear $= \frac{73 \times 30 + 71 \times 20}{50}$
$= 72.2$
$∴$ Mean score of class is $72.2$

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A class consist of 50 students out of which 30 are girls. The mean marks scored by girls in a test is 73 (out of 100) and and that of boys is 7171. Determine the mean score of the whole class.

Mean score of 30 girls =73total score =73×30Mean score of 20 boys =71total score =71×20Mean score of clear =73×30+71×2050=72.2∴ Mean score of class is 72.2

A class consist of $50$ students out of which $30$ are girls. The mean marks scored by girls in a test is $73$ (out of $100$ ) and and that of boys is $7171$ . Determine the mean score of the whole class.

Mean score of $30$ girls $= 73$
total score $= 73 \times 30$
Mean score of $20$ boys $= 71$
total score $= 71 \times 20$
Mean score of clear $= \frac{73 \times 30 + 71 \times 20}{50}$
$= 72.2$
$∴$ Mean score of class is $72.2$