Once the parameters have been calculated, the resulting equation can be used to make predictions about a value of y given a value of x, provided that the x value is in the same range of x-values that were used to derive the equation.

For example, if x = 350 mg/dL, what is the expected value of y? To find the answer, substitute the known value of x into the equation.

When the concentration is 350 mg/dL, we expect the absorbance to be about 0.7.