Unformatted text preview: students that will want to enroll. Suppose the number of students wishing to enroll in a statistics class is normally distributed with mean 100 and a variance of 49 . Find the smallest classroom size suﬃcient to hold all interested students with probability at least 90% . Show all your steps and explain your solution procedure. P ( X ≤ c ) = P ± X100 7 ≤ c100 7 ² = P ± Z ≤ c100 7 ² = Φ ± c100 7 ² = 0 . 9 . (6) Observe Φ(1 . 28) ≈ . 9, hence c100 7 = 1 . 28 ⇒ c = 100 + 7 × 1 . 28 = 100 + 8 . 96 ≈ 109 . (7) www.ece.drexel.edu/weber 1 May 14, 2010...
View
Full Document
 Spring '04
 Eisenstein
 Normal Distribution, Standard Deviation, Probability theory, Steven Weber, smallest classroom size

Click to edit the document details