URGENT BRAINLIEST GIVEN
Mr Brown gives his class a test.
The 10 girls in the class get a mean mark of 70%.
The 15 boys in the class get a mean mark of 80%.
Nick says that because the mean of 70 and 80 is 75 then the mean mark for the whole class in the test is 75%. Nick is not correct.
Is the correct mean less than or greater than 75%?
You must justify your answer.

Respuesta :

This is the way I do it to find the average.

10 girls times 70 = 700

15 boys times 80= 1200

700+1200=1900 all their scores

1900÷25 (number of boys and girls)=76 or 76%