Chapter 14, Problem 1P

To determine

Ranking the alternatives.

Explanation of Solution

The important attributes need to consider before purchasing a car are stylish design, fuel economy, price of the car, maintenance cost per 1,000 miles, and useful life.

Table 1 shows the information regarding three alternative cars.

Table 1

	Alternative
Attributes	1	2	3
Stylish design	Excellent	Good	Poor
Fuel economy	28	31	30
Price	50,000	48,000	47,000
Maintenance cost per 1,000 miles	200	210	215
Useful life	5	5	4.8

An attribute can be ranked (Higher rating is preferable) by using the following formula:

$\text{Rating}=\frac{\text{Outcome}\text{being made}-\text{worst}\text{outcome}}{\text{Best}\text{outcome}-\text{worst}\text{}\text{outcome}}$        (1)

An attribute can be ranked (Lower rating is preferable) by using the following formula:

$\text{Rating}=\frac{\text{Worst}\text{outcome}-\text{outcome}\text{being made}}{\text{Worst}\text{outcome}-\text{Best}\text{}\text{outcome}}$        (2)

Substitute the respective values in Equation (1) to calculate the rank of fuel economy for alternative 1.

$\begin{array}{c}\text{Rating}=\frac{\text{28}-\text{28}}{\text{31}-\text{28}}\\ =\frac{0}{3}\\ =0\end{array}$

The rating is 0.

Table 2 shows the rating of attributes for respective alternatives, which are obtained by using Equations (1) and (2).

Table 2

	Alternative
Attributes	1	2	3
Stylish design	1	0.5	0
Fuel economy	0	1	0.67
Price	0	0.67	1
Maintenance cost per 1,000 miles	1	0.33	0
Useful life	0.09	1	0

The highlighted value indicate the best alternative for specific attributes.