I didn't pay attention in class for a few days and now I'm lost. if somebody could at least explain proportions I would be very thankful.

Answer:
A proportion is a comparison of two numbers that each represent the parts of a whole. Essentially, a proportion says that two fractions are the same, even if the amount is different. For example, 1/2 of 10 marbles is the same proportion as 1/2 of 50 marbles.
Step-by-step explanation: