Question

Which situation BEST describes a direct variation?

a. Each of the diners at a table will leave a $3 tip. The more diners sitting at a table, the greater the total tip.
b. A manager estimates that a construction project will take 60 days with 2 workers. The more workers hired, the fewer the days to complete the project.
c. A hot dog stand owner opens her store with 500 hot dogs. The fewer the number of hot dogs cooked, the greater the number of hot dogs uncooked.
d. A truck driver fills the gas tank in a truck to start a 100-mile trip. The farther the driver travels, the less gasoline will be left in the gas tank of the truck.

Answer 1

The best example of direct variation is when each diner at a table leaves a $3 tip, meaning the total tip is directly proportional to the number of diners.

Step-by-step explanation:

The situation that BEST describes a direct variation is a. Each of the diners at a table will leave a $3 tip. The more diners sitting at a table, the greater the total tip. This represents a direct variation because the total tip is directly proportional to the number of diners: if the number of diners increases, the total tip increases at a constant rate of $3 per diner.

Direct variation is described by the equation y = kx, where y is the dependent variable, x is the independent variable, and k is the constant of variation. In this case, the total tip (y) varies directly with the number of diners (x) with a constant of variation (k) of $3.