Question 1139522
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Informally....<br>
For every 4 boys, there are 5 girls.
Therefore, out of every 9 students, 4 are boys.
Therefore, 4/9 of the students are boys.<br>
Formally....<br>
The ratio of boys to girls is 4:5.
So let 4x be the number of boys and 5x be the number of girls.
Then 4x+5x = 9x is the total number of students.
Then the fraction of boys in the class is 4x/9x = 4/9.