Using proportions, it is found that 420 students in the school would be expected to say their favorite class is Reading or Math.
What is a proportion?
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, out of 90 students, 20 + 40 = 60 students prefer reading or math. How many do out of 630? Thus, the rule of three is given by:
60 prefer reading of math - 90 students.
n prefer reading of math - 630 students.
Applying cross multiplication:
90n = 630 x 60
n = 630 x 60/90
n = 7 x 60
n = 420
420 students in the school would be expected to say their favorite class is Reading or Math.
More can be learned about proportions at https://brainly.com/question/24372153
