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.
<u>a) the cost of a phone plane is $25 per month and 10 cents per minute.</u>
Answer : NO
Because payment doesn't changes abruptly as you can get payment even for 2 seconds using given pattern.
<u>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.</u>
Answer : NO
Because payment doesn't changes abruptly as you can get payment even for 1 minute using given pattern.
<u>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.</u>
Answer : NO
Because payment doesn't changes abruptly. cost is just calculated in two pieces which is more like piecewise function.
<u>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.</u>
Answer : YES
Because the payment changes abruptly from $40 to $75 when number of minutes goes over 250
