Given:
Of the 50 students in the cafeteria, 7 have red hair.
Total number of students = 750
To find:
The proportion that could be used to predict the number of students who have red hair.
Solution:
Let x represent the number of students who have red hair.
The ratio of student having red hair to the total number of students are
The number of students having red hair is proportional to the total number of students. So, the above ratios are equal.
Multiply both sides by 750.
Therefore, the required equation is and the number of students who have red hair is 105.