Final answer:
To find the total number of books read by the youth group, we need to sum up the number of books read by the girls and the boys. The girls read a total of 36 books, and the boys read a total of 88 books. Therefore, the total number of books read by the youth group members is 124.
Step-by-step explanation:
To find the total number of books read by the youth group, we need to find the sum of the number of books read by the girls and the boys.
The mean number of books read by the girls is 4, and there are 9 girls in the group. So the total number of books read by the girls is 4 * 9 = 36.
The mean number of books read by the boys is 8, and there are 11 boys in the group. So the total number of books read by the boys is 8 * 11 = 88.
Therefore, the total number of books read by the youth group members is 36 + 88 = 124.