Question: how to find the percentage of area under a normal curve?
Answer: To find the percentage of the area that lies "above" the z-score, take the total area under a normal curve (which is 1) and subtract the cumulative area to the left of the z-score. In part a, 73 had a z-score of -1.34615 with a cumulative area to the left of 0.0901 or 9.01%.