Question: how to calculate the probability of random sample?
Answer: From the table, you determine that P(Z > 1.44) = 1 – 0.9251 = 0.0749. So if it's true that 38 percent of all students taking the exam want math help, then in a random sample of 100 students the probability of finding more than 45 needing math help is approximately 0.0749 (by the Central Limit Theorem).