Let's begin by listing out the information given to us:
We will pick 2 coordinates that lie along the straight line. We have: (x, y) = (1, 4.8), (4, 1.8)
We will proceed to calculate the Slope of the line as shown below
Slope (m) = Δy/Δx = (1.8-4.8)/(4-1) = -3/3 = - 1
Slope (m) = -1
The next thing is to obtain the formula for the straight line. This is down below:
Using the Point-Slope equation, we have:
y - y1 = m(x - x1)
(x1, y1) = (1, 4.8)
⇒ y - 4.8 = -1(x-1)
y = -x + 1 + 4.8
y = -x + 5.8
When x = 5, the value of y is:
y = -x + 5.8 ⇒ y = -5 + 5.8 = 0.8y = 0.8
y = 0.8
Therefore, when x is 5, y equals 0.8