Answer:
y = 1.5x + 1.5
Explanation:
Since it says it is growing at a constant rate, it means that is linear.
The linear formula follows this form: y = mx + c, where m is the gradient and c is the y-intercept
To find the gradient, you sub the values into the gradient formula.
That would be 4.5 - 3.0 divided by 2-1
That would be 1.5/1 = 1
Hence the gradient is 1.5
y = 1.5x + c
To find c, you sub in one point into the equation
I'm going to go with (3, 6.0)
6 = 1.5*(3) + c
6 - 4.5 = c
c = 1.5
Hence the formula is: y = 1.5x + 1.5