Answer:
Step-by-step explanation:
Let the equation of the line representing relation between the euros and dollars is,
E = mD + b
Where 'E' = Number of euros
D = Number of dollars
m = slope of the line
b = y-intercept
Slope of a line which passes through two points (120, 90) and (400, 300) will be,
m = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex] = [tex]\frac{300-90}{400-120}[/tex]
m = 0.75
Equation of the line passing through (120, 90),
90 = 0.75(120) + b
b = 90 - 90 = 0
Therefore, equation of the line will be,
E = mD
E ∝ D
Here m = Proportionality constant
And the relation between the numbers of Euros and US dollars is a proportional relationship.
