1. Normal Probability Distribution Using Normal Distribution for Probability

2. Find the following proportions of the following: (1) z <.85 (2) z >.85 (3) z > 2.66 (4) −.1 < z <.1 Warm-up =.8023 =.1977 =.0039 =.0796

3. Normal Distribution as Probability Distribution

4. Example Problem 1 Supposed there are a sample survey of 400 undergraduates students who have been asked if they are going to report cheating between 2 people in a quiz. The study showed that 12% would answer YES. What is the probability that the survey result differs from the truth about the population by more than 2 percentage point? p = 0.12 Ṕ = 0.12 N (0.12, 0.016) N(mean, sd) Ṕ =0.10 Ṕ =0.12 Ṕ =0.14

5. Ṕ =0.10 Ṕ =0.12 Ṕ =0.14 What is the probability that the survey result differs from the truth about the population by more than 2 percentage point? P(0.10 ≤ Ṕ ≤ 0.14) = P (Z-score 1 ≤ Ṕ ≤ Z- score 2) = P (-1.25 ≤ z ≤ 1.25) = 0.8944 - 0.1056 = 0.7888 = 1- 0.7888 =.2112 Therefore, about 21% of sample results will be off by more than 2 percentage point