Question 21 (1 point) This table shows the input and output values for a linear function f(x). What is the positive difference o
f outputs for any two inputs that are four values apart? x −3 −2 −1 0 1 2 3 f(x) −1.5 −1 −0.5 0 0.5 1 1.5 Enter your answer in the box. (Enter the number and nothing else)