Instruction 13 -Referring to Instruction 13

question 210

Multiple Choice

Instruction 13.41
An automotive engineer would like to be able to predict automobile fuel economy. She believes that the two most important characteristics that affect economy are engine power and the number of cylinders (4 or 6) of a car. She believes that the appropriate model is
$\begin{array}{l}Y = 40 - 0.05 X _ { 1 } + 20 X _ { 2 } - 0.1 X _ { 1 } X _ { 2 }\\\\\text { where } \begin{aligned}X _ { 1 } & = \text { engine power } \\X _ { 2 } & = 1 \text { if } 4 \text { cylinders, } 0 \text { if } 6 \text { cylinders } \\Y & = \text { economy expressed as kilometres. }\end{aligned}\end{array}$
-Referring to Instruction 13.41,the fitted model for predicting economy for 6-cylinder cars is______.

• A)60 - 0.10X₁
• B)40 - 0.10X₁
• C)40 - 0.05X₁
• D)60 - 0.15X₁

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Definitions:

Expand

To express a mathematical expression in an extended form by removing parentheses or factoring, usually by applying the distributive property.

Binomial Theorem

A formula for expressing the powers of sums, which identifies the expansion of a binomial raised to any positive integer power.

Approximate

To estimate or come close to an actual value, not exact but within a reasonable range.

Binomial Coefficient

A numerical factor that represents the number of ways to choose a subset of elements from a larger set, commonly expressed as "n choose k."