Shipping company IPS has shipping rates that are a function of the weight of the parcel. For packages weighing less than or equal to 7 pounds, they charge $ 1.25 per pound. For packages weighing between 7 and 13 pounds, they charge $ 2.25 per pound. If packages weigh 13 pounds or more, they charge $ 3.5 per pound. IPS refuses to ship any parcel weighing more than 98 pounds. There is also a flat fee of $ 1 for all deliveries and an additional fee of $ 3 for all deliveries weighing 13 pounds or more.

Complete the following description of a piecewise function so that is describes the shipping costs [FONT=MathJax_Math-italic]C[FONT=MathJax_Main]([/FONT][FONT=MathJax_Math-italic]x[/FONT][FONT=MathJax_Main])[/FONT][/FONT] in dollars as a function of the weight

*x*in pounds.

So far I have:

(1.25 + 1) if

*x*is in the interval (-inf,7]

(2.25 +1) if

*x*is in the interval (7,13)

(3.50+1+3) if

*x*is in the interval [13,inf)

Apparently everywhere is wrong. So I could use some help figuring out why. It would be very much appreciated.