You can learn the rate for something by looking at the slope of a graph. You can also look at the start-up fee or initial cost by looking at the y-intercept of the graph. Additionally, you can get an idea of whether you are making a profit or loss in a business, how far you can throw, or many other real life situations.
Answer: rate for postage purchased at the Post Office will remain at $0.55 (no change from 2020). Each additional ounce for a First Class Mail letter will cost $0.20, a five cent increase from 2020.
