Mrs. Gifford's class consists of 15 girls and 25 boys.
the class mean was 80 and the mean girl’s scores was 75. What was the mean of the boy’s scores?
Bill, you have now posted this same question 7 times since yesterday. You received a variety of ways to get the answer.
Ms Sue even told you not to post it again, so here it is once more
(15*75 + 25x)/(15+25) = 80
Now just find x.
Total points / total students = average
To find the mean of the boys' scores, we need to know the total score of the boys in the class. With the given information, we can calculate it.
First, let's calculate the total score of all the students in the class. Since we know the class mean, we can multiply it by the total number of students:
Total score of all students = Class mean × Total number of students
Total number of students = Number of girls + Number of boys
In this case, the number of girls is 15 and the number of boys is 25. So:
Total number of students = 15 girls + 25 boys = 40 students
Now that we know the total number of students, we can calculate the total score of all students:
Total score of all students = Class mean × Total number of students = 80 × 40 = 3200
Next, let's calculate the total score of all the girls in the class. We know the mean girl's score is 75. To find the total score of the girls, we can multiply their mean score by the number of girls:
Total score of girls = Mean girl's score × Number of girls = 75 × 15 = 1125
Now, to find the total score of the boys, we subtract the total score of the girls from the total score of all the students:
Total score of boys = Total score of all students - Total score of girls = 3200 - 1125 = 2075
Finally, to find the mean of the boys' scores, we divide the total score of the boys by the number of boys:
Mean of boys' scores = Total score of boys ÷ Number of boys = 2075 ÷ 25 = 83
Therefore, the mean of the boys' scores is 83.