In a recent year, the scores for the reading portion of a test were normally distributed, with a mean of 21.5 and a standard deviation of 5.3. Complete parts (a) through (d) below. (a) Find the probability that a randomly selected high school student who took the reading portion of the test has a score that is less than 20 The probability of a student scoring less than 20 is (Round to four decimal places as needed.)