Which of the following situations could be graphed using a step function? a) the cost of a phone plane is $25 per month and 10 cents per minute. b) mcdonald's employees get paid $7.25 per hour up to 40 hours and they make $10.88 per hour if they work over $40 hours. c) a t-shirt company charges a flat fee of $35 plus $4 per shirt for up to 100 shirts, if more than 100 shirts are ordered, the cost is $35 plus $2 per shirt. d) a phone company charges $40 if you use less than 250 minutes, $75 if you use between 250-450 minutes, and $100 for more than 450 minutes.

We know that step function is a function that increases or decreases abruptly from one constant value to another. So we will use this logic to decide which of the following can be graphed using step function.

a) the cost of a phone plane is $25 per month and 10 cents per minute.

Answer : NO

Because payment doesn't changes abruptly as you can get payment even for 2 seconds using given pattern.

b) McDonald's employees get paid $7.25 per hour up to 40 hours and they make $10.88 per hour if they work over $40 hours.

Answer : NO

Because payment doesn't changes abruptly as you can get payment even for 1 minute using given pattern.

c) A t-shirt company charges a flat fee of $35 plus $4 per shirt for up to 100 shirts, if more than 100 shirts are ordered, the cost is $35 plus $2 per shirt.

Answer : NO

Because payment doesn't changes abruptly. cost is just calculated in two pieces which is more like piecewise function.

d) A phone company charges $40 if you use less than 250 minutes, $75 if you use between 250-450 minutes, and $100 for more than 450 minutes.

Answer : YES

Because the payment changes abruptly from $40 to $75 when number of minutes goes over 250

126 maybe. sorry