Answer:
Y = 1.2X + 55
Step-by-step explanation:
As the blue line is a straight line, so that the equation describing it has the following form:
Y = a.X + b (1)
As the blue line intersects the vertical axis at 55 cm, so that it crosses point A with [tex]X_{A} = 0; Y_{A} = 55[/tex] . As point A is on the blue line, so that:
+) [tex]Y_{A} = a.X_{A} +b[/tex]
=> 55 = a.0 + b
=> 55 = b
As the blue line intersects the pink line at point B(12.5; 70) so that [tex]X_{B} = 12.5; Y_{B} = 70[/tex] . As point B is on the blue line, so we have:
+) [tex]Y_{B} = a.X_{B} +b[/tex]
=> 70 = a*12.5 + b
As b = 55
=> 70 = 12.5*a + 55
=> 12.5* a = 70 - 55 = 15
=> a = 15/12.5 = 1.2
Replace a = 1.2 and b = 55 into equation (1), we have:
Y = 1.2X + 55
