Cell phones in the home A survey found that 73% of Americans have a home phone, 83% have a cell phone and 58% of people have both. a) If a person has a home phone, whats the probability that they have a cell phone also? b) Are having a home phone and a cell phone independent events? Explain. c) Are having a home phone and a cell phone mutually exclusive? Explain.

Week 9: Confidence Intervals 1 November 2016 Basic Statistics for Research Professor HK Dong Wendy Liu If the population is not normal: We can apply the Central Limit Theorem Sample means from the population will be approximately normal as long as the sample size is large enough Properties of the sampling distribution: Mean of the sample means is the population mean: Standard deviation of the sample means is the population standard deviation divided by the square root of sample size: For most distributions, n>30 will give a sampling distribution that is approximately normal Z-value for sampling distributions of x-bar Binomial distribution conversion to z-score: The normal distribution can be used to approximate the binomial distr