We can use a proportion to estimate the number of students who could be expected to bring their lunch:
9 out of 15 students brought their lunch from home.
Let x be the number of students in the school who bring their lunch from home.
So we can set up the proportion:
9/15 = x/500
We can solve for x by cross-multiplying:
9 * 500 = 15x
x = (9 * 500) / 15
x = 300
Therefore, we can expect that 300 out of 500 students in the school bring their lunch from home.