Test scores on a university admissions test

Test scores on a university admissions test are normally distributed, with a mean of 500 and a standard deviation of 100.a. What is the probability that a randomly selected applicant scores between 425 and 575?b. What is the probability that a randomly selected applicant scores 625 or more? Introduction to Statistics 7 2 marksc. What is the probability that a randomly selected applicant scores less than 500?D. twenty per cent of test scores exceed what value?X ? n(500; 100) P(X ? x) = 0.20 P((X – 500)/100 ? (x – 500)/100) = 0.20 P(Z ? z) = 0.20 z = 0.84 0.84 = (x – 500)/100 x = 584 P(X ? 584) = 0.20