Answer:
[tex]x = 14ft[/tex]
Step-by-step explanation:
Given
[tex]Actual\ Length = 21ft[/tex]
Model:
[tex]3\ ft = 2\ in[/tex]
Required
Determine the length of the replica
Represent the model as a ratio:
[tex]Ratio = 3\ in:2\ ft[/tex]
Convert to fraction
[tex]Ratio = \frac{3\ in}{2\ ft}[/tex]
Represent the actual lengths as a ratio
[tex]Ratio = 21\ ft : x[/tex]
Where x is the length of the replica
Convert to fraction
[tex]Ratio = \frac{21\ in}{x}[/tex]
Equate both ratios (because they are in proportion)
[tex]\frac{3\ in}{2\ ft} = \frac{21\ in}{x}[/tex]
[tex]\frac{3}{2\ ft} = \frac{21}{x}[/tex]
Cross Multiply:
[tex]3 * x = 21 * 2\ ft[/tex]
[tex]3x = 42\ ft[/tex]
Solve for x
[tex]x = \frac{42ft}{3}[/tex]
[tex]x = 14ft[/tex]
Hence, the length of the replica is 14ft
