The linear function that models the problem is
y = -0.3x + 253
How to model the required equation
The linear equation is written in the slope intercept form
y = mx + c
definition of variable to suit the problem
y = output variable
m = slope
x = input variable
c = y intercept
The equation as described in the problem is represented using linear function as as follows
using points from the table:
(170, 203) and (150, 209)
m = (203 - 209) / (170 - 150)
m = -6 / 20
m = --3/10 = -0.3
Lets find the equation using a third point (190, 196)
y - 196 = -0.3 (x - 190)
y = -0.3x + 57 + 196
y = -0.3x + 253