An article suggested that yield strength (ksi) for A36 grade steel is normally distributed with=42and=5.5.

(a) What is the probability that yield strength is at most38? Greater than63? (Round your answers to four decimal places.)

at most 38 _____________

greater than 63 _____________

(b) What yield strength value separates the strongest 75% from the others? (Round your answer to three decimal places.) _____________ksi You may need to use the appropriate table in theAppendix of Tablesto answer this question.