Question

3 scale up or scale down to determine each unknown quantity. b) (12 inches)/(1 foot) = ?/(18 feet)

Explanation:

Step1: Identify the proportion

We have a proportion \(\frac{12 \text{ inches}}{1 \text{ foot}}=\frac{?}{18 \text{ feet}}\). Let the unknown quantity be \(x\) (in inches). So the proportion is \(\frac{12}{1}=\frac{x}{18}\).

Step2: Solve for \(x\)

Using cross - multiplication, we know that in a proportion \(\frac{a}{b}=\frac{c}{d}\), \(a\times d = b\times c\). Here, \(a = 12\), \(b = 1\), \(c=x\), \(d = 18\). So \(1\times x=12\times18\).
Calculating \(12\times18\), we get \(x = 216\).

Answer:

216 inches