please help me im almost done please ive been working all day someone just give me an example and ill give brainliest or however u spell it :)

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

Which of the following graphs could represent a cubic function?

How is the interquartile range calculated?