Answer
a. $8\ mi/h$
b. see explanations.
Work Step by Step
a. Based on the given table, we have $\lim_{x\to3}f(x)=8\ mi/h$ which means that when your nose approaches the fan, the breeze you feel will be close to a speed of $8\ mi/h$.
b. As the fan is at $x=3$, it is not possible for your nose to be at $x=3$ (injury may occur). While $f(3)$ gives an exact function value at $x=3$, the value of $\lim_{x\to3}f(x)$ represent the limit to which the function approaches when $x\to 3$.