Let
x ----> total number of students Lake City Jr. High Students
we have that
12 out of every 18 rides a bus to school
160 ride a bus to school
Applying proportion
18/12=x/160
solve for x
x=(18/12)*160
x=240 total students
so
9 out of every 15 live in Lake City
that means
6 out of every 15 does not live in Lake City
Applying proportion
y -----> students that not live in Lake City
6/15=y/240
solve for y
y=(6/15)*240
y=96
therefore
96 students do not live in Lake City