No,2
It's a linear function : f(x) = mx + b OR y = m.x + b (since f(x) = y.
Let's calculate the slope m→ m=(y₂-y₁)/(x₂-x₁)
The pair of the 1st data is (4 ; 7.5)
The pair of the 2nd data is (6 ; 9)
Then m = (9-7.5)/(6-4) → m = 0.75 (you can verify it with any other pair).
y = 0.75x + b. Now let's calculate b (which is the y-intercept) by plugging in any pair, let's take the last one (10,12)
12 = (0.75)(10) + b → b= 12 - 7.5 → b = 4.5
The equation becomes y = 0.75x + 4.5 OR f(x) = 0.75x +4.5
