There would be 12 girl students in a class of 21 students.
What is proportion?
"A proportion is a mathematical statement where two or more ratios are equivalent."
We have been given that, the ratio of girls to the total number of students in class is 4:7
We need to find the number of girl students if the class has 21 students in all.
Let 'n' represents the number of girl students.
⇒ [tex]\frac{4}{7} = \frac{n}{21}[/tex]
⇒ [tex]4\times 21 = n\times 7[/tex] ......................(cross product)
⇒ [tex]84 = n\times 7[/tex]
⇒ [tex]n=\frac{84}{7}[/tex] ......................(Divide each side by 7)
⇒ [tex]n=12[/tex]
Hence, there would be 12 girls if class has 21 students in all.
Learn more about ratios and proportion here:
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