#### Answer

a) $P(x < 66) = 0.1210$
b) $P(66 < x <72)$ = 0.6949
c) $P(x > 72) = 0.1841$
d) No event here is unusual.

#### Work Step by Step

a) $P(x < 66)$
$z = \frac{66-69.4}{2.9} \approx -1.17$
$P( z 72)$
$P(z > 0.90) = 1-0.8159 = 0.1841$
Therefore $P(x > 72) = 0.1841$
d) No event here is unusual. We can infer this because the z score of each value is less than 2. Also, the probability of getting each value is above 0.05.