On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the two means)
On the second test, the class mean was 80 and the mean girl’s scores was 75. What was the mean of the boy’s scores?
I WOULD LIKE THE ANSWER TO THE SECOND PART
1 answer
The class mean depends on the ratio of girls to boys. You can easily see that if there are 5 times as many girls as boys, then the boys' scores affect the class mean less than the girls' scores.
2 answers