n=800 x=632 Example: The National Association of Music Merchants surveyed 800 parents of children 5-18, and 632 of them said that music education has a positive effect on academic performance. Assuming these parents to be a random sample, we would like to construct a 95% confidence interval for the proportion of parents who believe that music education has a positive effect on academic performance. One example by hand for understanding - you will use your calculator when finding confidence intervals (see next slide) Check the assumptions and conditions. ✓ We have a simple random sample. The sample size of 800 is less than 10% of the population of all parents. ✓ It's safe to assume that the individuals within the sample are independent. ✓ The sample contains 632 successes and 168 failures 800-632