In a recent year, the ACT scores for the math portion of the test were normally distributed,

Question:

In a recent year, the ACT scores for the math portion of the test were normally distributed, with a mean of 21.1 and a standard deviation of 5.3. Find the probability that a randomly selected high school student who took the math portion of the ACT has a score that is
(a) Less than 16,
(b) Between 19 and 24,
(c) More than 26,
(d) Identify any unusual events.
Explain your reasoning.