Answer
$P(p̂ \leq 0.18) = 0.0336$. This implies that about 3 out of 100 samples of size n = 300 will result in 18% or less smokers. Yes, it is unusual, as p < 0.05.
Work Step by Step
Using data from part (a) for $p̂ \leq 0.18$, we have:
$z = \frac{0.18 - 0.224}{0.024} = -1.83$
$P(p̂ \leq 0.18) = P(z > -1.83) = 0.0336$
