of Increase (decreases) in the desired width for a fixed level of confidence. 13. Suppose the students' mathematics scores conform to a normal distribution with A = Yo ,0 = 10. a. What proportion of students will have scores higher than 94.6? b. What proportion of students will have scores between 49.2 and 100.8? c. What score will be exceeded by 10% of the students? d. Suppose a random sample of n = 64 test scores is selected; what is the standard error of the sampling distribution