Solution
For this case we need to remember that the general equation for a line is given by:
y= mx+ b
Where m represent the slope and b the intercept
And we can find the slope with this formuala:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]And we can use (50, 725) and (100,1325) and we have:
[tex]m=\frac{1325-725}{100-50}=12[/tex]And the intercept would be:
725 = 50*12 +b
b= 725 - 600
b= 125
and the equation would be given by:
y= 12 x + 125
And the y intercept represent the starting value of 125$ no matter the number of guests