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
[tex]Ratio_1=\dfrac{7}{50}[/tex]
[tex]Ratio_2=\dfrac{x}{750}[/tex]
The number of students having red hair is proportional to the total number of students. So, the above ratios are equal.
[tex]\dfrac{x}{750}=\dfrac{7}{50}[/tex]
Multiply both sides by 750.
[tex]\dfrac{x}{750}\times 750=\dfrac{7}{50}\times 750[/tex]
[tex]x=7\times 15[/tex]
[tex]x=105[/tex]
Therefore, the required equation is [tex]\dfrac{x}{750}=\dfrac{7}{50}[/tex] and the number of students who have red hair is 105.
