Respuesta :
The mean mark of the boys is 0.95 or 95% if the mean mark of the class was 80%.
What is mean?
It is defined as the single number that represents the mean value for the given set of data or the closed value for each entry given in the set of data.
Mean mark of the girls = 75% = 0.75
Number of girls = 30
0.75 = sum of the marks of girls/30
The sum of the marks of girls = 0.75×30 = 22.5
Mean of the class = 80% = 0.80
0.80 = The sum of the marks of whole class/40
The sum of the marks of whole class = 0.80×40 = 32
The sum of the marks of boys = 32 - 22.5 = 9.5
Mean mark of the boys = 9.5/10 = 0.95 or 95%
Thus, the mean mark of the boys is 0.95 or 95% if the mean mark of the class was 80%.
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