Choose the situations that state an appropriate domain for the function.

a function predicts the number of square feet in a house in terms of the number of bedrooms. an appropriate domain for the function is positive real numbers.

a grocery store sells salmon by the pound. the function c(x) represents the cost, in dollars, of x pounds of salmon. an appropriate domain for the function is positive rational numbers.

a ball was thrown into the air with an initial velocity of 65 feet per second. the height of the ball after t seconds is represented by the equation h = 65t − 16t2. an appropriate domain for the function is positive rational numbers.

a taxi company charges $2.50 plus $1.75 for each mile driven. a function c(x) shows how much a taxi fare cost. an appropriate domain of c(x) is all whole numbers.

lindsay's lemonade stand sells lemonade for $0.75 per cup. her daily profit is modeled by p(c) = 0.75c – 8.5 where profit, p, is a function of cups, c. an appropriate domain of p(c) is all integers.