PLEASE HELP THERE ARE TWO PARTS!!

The graph shows the relationship between the United States dollar and
the euro, the currency of the European Union, in December 2011. Part A:
What is the constant of proportionality shown in the graph? *
Exchange Rate (December 6, 2011)
VA
(400, 300)
300
Number of euros
200
(250, 187.50)
100
(120,90)
100 200 300
400
Number of US dollars
I

PLEASE HELP THERE ARE TWO PARTS The graph shows the relationship between the United States dollar and the euro the currency of the European Union in December 20 class=

Respuesta :

Answer:

The constant of proportionality of the graph is 0.75

Step-by-step explanation:

The coordinates of the points on the lines are;

(400, 300), (250, 187.5), and (120, 90)

Which can be written in a tabular form as follows;

Number of US dollars   [tex]{}[/tex]                       Number of euros

120                                 [tex]{}[/tex]                        90

250                                [tex]{}[/tex]                        187.5

400                                [tex]{}[/tex]                        300

Given that the graph is a straight line graph, we can represent the graph with the straight line equation, y = m·x + c

Where;

c = The y-intercept (where the graph meets the y-axis) = 0

m = The slope = The constant of proportionality

[tex]Slope, \, m =\dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]

[tex]m =\dfrac{300-90}{400-120} = \dfrac{210}{280} = 0.75[/tex]

We have, y = m·x = 0.75·x.

Therefore, the constant of proportionality of the graph = 0.75.