A class consists of 50 students out of which 30 are girls. -Maths 9th

A class consists of 50 students out of which 30 are girls. -Maths 9th
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1 Answer

Answer :

Mean marks scored by girls ( x̅1 ) = 73  Number of girls (n1) = 30  Mean marks scored by boys ( x̅2 ) = 71  Number of boys (n2) = 50 - 30 = 20 Mean score of the whole class ( x̅12 ) = n1  x̅1   + n2  x̅2 /n1 + n2 =  30 x 73 + 20 x 71/30 + 20 = 2190 + 1420/50 = 3610/50 x̅ 2 = 72.2
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Description : Given are the scores (out of 25) of 9 students in a Monday test : 14, 25, 17, 22, 20, 19, 10, 8 and 23 -Maths 9th

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