Answer:
20%
Explanation:
Because 144 OUT OF the 180 seventh grade students attended, this would represent 144/180.
But since we are trying to solve how many did NOT attend the dance, you must subtract 144 from 180 which equals 36. So 36/180 did not attend the dance.
But to make it a percentage, you divide 36/180. Fraction and percentage are like buddies! That's why it is very simple to make a fraction into a percentage.
36/180 can be simplified to 1/5, which as a decimal, is 0.20.
0.20 is same as 20%, so this should be the students that did not attend the dance.
I hope this helps. If this is wrong, I truly apologize...