In 2000, as reported by ACT Research Service, the mean ACT Math score was μ=20.7. If ACT Math scores are normally distributed with σ = 5, answer the following questions.
a)What is the probability that a randomly selected student has an ACT Math score less than18?
b)What is the probability that a random sample of 10 ACT test takers had a mean ACT Math score less than 18?