Question

A postal delivery service charges $3.40 per package and then an additional $0.50 per ounce the package weighs. The function can be modeled by f(x)= 0.5 +3.4. Tom ships 4 packages with the following weights: 2 ounces, 3.5 ounces, 15 ounces, and 21.3 ounces. Write four statements using function notation that evaluate the function given each of these weights. Interpret the results in terms of the context of the function.

Answer 1

• f(2) = 0.5·2 +3.40 = 4.40
• f(3.5) = 0.5·3.5 +3.40 = 5.15
• f(15) = 0.5·15 +3.40 = 10.90
• f(21.3) = 0.5·21.3 +3.40 = 14.05

Explanation:

The function you're to evaluate is

... f(x) = 0.5x +3.40

Using function notation, the value for x = 2 is ...

... f(2)

For x = 3.5, the value is ...

... f(3.5)

and so on.

To actually evaluate the function, you need to put the value where x is in the function definition and do the arithmetic:

... f(2) = 0.5·2 + 3.40 = 1.00 +3.40 = 4.40

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The function gives the charge for a package based on its weight in ounces. The result of evaluating the function for the given weights is that you find the charges for delivery of those packages.