A psychologist has been studying eye fatigue using a particular measure, which she administers to students after they have worked for 1 hour writing on a computer. On this measure, she has found that the distribution follows a normal curve. The test of eye fatigue has a mean of 15 and a standard deviation of 5. Using a normal curve table, what score on the eye fatigue measure would a person need to have to be in the top 40%?