Given:
Distance between New york and Washington DC in ruler is, d(r) = 2 1/2 inches=2.5 inches.
Actual distance between New york and Washington DC is, d(a) = 200 miles.
The objective is,
a) To find the scale ratio of map
b) To write the equation of relationship
c) To find the actual distance if distance between New york and Atlanta in map is 8.75 inches.
a)
The scale ratio can be calculated as,
[tex]\begin{gathered} r=\frac{d(a)}{d(r)} \\ r=\frac{200}{2.5} \\ r=80\text{ miles per inch.} \end{gathered}[/tex]Hence, the scale ratio of map is 80 miles per inch.
b)
Consider the actual distance as Y (miles) and the distance in map as X (inches).
The equation can be represented as,
[tex]\begin{gathered} Y\propto X \\ Y=rX \end{gathered}[/tex]Here, r represents the proportionality contant which is the scale ratio of the map.
Hence, the required equation is Y = rX.
c)
The actual distance between New York City and Atlanta can be calculated using the equation obtained in part (b).
It is known that r = 80 miles per inch and the value of X is given as 8.75 inches.
Substitute the obtained values in the equation.
[tex]\begin{gathered} Y=80\cdot8.75 \\ Y=700\text{ miles} \end{gathered}[/tex]Hence, the actual distance between New York City and Atlanta is 700 miles.