The equation y = 3.25x + 0.50 models the situation, where x is the number of pounds of granola purchased, and y is the total cost. Which statement about the equation is true?

Granola costs $3.25 per pound.
Granola comes in boxes that hold 0.5 pounds.
The total cost of granola is $3.75.
There are 3.25 pounds of granola in a 0.5-pound box.