The three functions describe an amount y of an antihistamine medication (in milligrams) in a person's bloodstream t hours after taking the dosage.

y≈500(0.67)^t
y≈500(0.9047)^4t
y≈500(0.7943)^60t

a.) What expressions, if any, are approximately equivalent? Explain how you know and show work.

b.) Describe the information given by each of the functions.