In a recent yoar, the scores for the reading portion of a test were normally distributed, with a mean of 20.4 and a standard deviation of 6.5 . Complete parts (a) through (d) below. (a) Find the probablity that a randomly selected high school student who took the reading portion of the test has a score that is less than 18. The probability of a student scoring loss than 18 is (Round to four decimal places as needed.).