Anyone know how to do this problem??

For each proportion find the unknown number x 1/5/8=×/15

Clara schumann is buying bagels for her coworkers, she buys a dozen bagels priced at $5.49 a dozen. the bakery's cost for making the bagels is $2.25 per dozen. what is the markup rate based on selling price on a dozen bagels?

Which of the following represents the range of the graph of f(x) below