If n=520 and ˆp=0.3, construct a 95% confidence interval about the population proportion. Round your answers to three decimal places. Preliminary: Is it safe to assume that n≤0.05 of all subjects in the population? Yes No Verify nˆp(1−ˆp)≥10. Round your answer to one decimal place. nˆp(1−ˆp)= Confidence Interval: What is the 95% confidence interval to estimate the population proportion? Round your answer to three decimal places. < p <

We wish to estimate what percent of adult residents in a certain county are parents. Out of 100 adult residents sampled, 72 had kids. Based on this, construct a 90% confidence interval for the proportion, p, of adult residents who are parents in this county.Give your answers as decimals, to three places. < p <

A USA based cable broadband company wants to compare the average customer satisfaction scores between its east coast and west coast customer bases. The customer survey asks for a score between 1 and 5, with 1 being poor and 5 being excellent. 174 east coast customers are surveyed, and the sample mean is 3.51 with a sample standard deviation (s) of 0.51. For the west coast, 355 customers are surveyed, and the sample mean is 3.24 with a sample standard deviation (s) of 0.52.

Congratulations, you just made a confidence interval! But wait, how did we decide on the width of the interval? The middle of the interval is the sample mean. We start there, and then the "wiggle room" we give on either side of that center is called the margin of error (MOE). There's a formula for margin of error: 0 MOE = 2* √T This formula consists of three values: o is the standard deviation, n is the sample size, and z is a multiplier that we choose based on the confidence level we need. Confidence levels are expressed as percentages, the most common are 90%, 95%, and 99%: * Confidence Z Level value 90% 1.645 95% 1.96 99% 2.576 Let's practice computing a margin of error. For our earlier example about houses, suppose the standard deviation was 14 years, and the sample size was 30. Use a confidence level of 95% and determine the margin of error: σ Remember, we'll use the formula MOE = 2* . First fill in the numbers for each part of the formula: √n = σ= n = Now put it all together,…