First part Conduct an investigation taking into consideration the following concepts: Confidence interval of a population mean Critical Z Score Confidence level Expected error level Significance level...

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First part Conduct an investigation taking into consideration the following concepts: Confidence interval of a population mean Critical Z Score Confidence level Expected error level Significance level Lower Confidence Limit (LCI) Upper Confidence Limit (LCS) Confidence interval precision Guiding questions to answer in writing: When calculating confidence intervals, what is the relationship between the sample size and the size of the standard error? When calculating confidence intervals, what is the relationship between the size of the confidence interval and the critical Z score used to calculate it? Write the statistical interpretation of any confidence interval for which you are 99% certain. List and explain the steps in calculating a confidence interval. The level of significance in the calculation of a confidence interval is symbolized by α. What is the relationship between α and the confidence level? Second part Answer all questions provided: Parameter Estimation and Confidence Intervals. 1. A marriage counselor applies the Global Distress Scale (EAG) which measures global marital discord. This scale consists of 43 true / false questions with a combined total score for the two spouses (Snyder, Willis, & Grady-Fletcher, 1991). She asks you to provide a rough estimate of the average score for her clientele. You obtain a random sample of 125 pairs and determine a mean EAG score of 59 points on the EAG scale with a standard deviation of 5.2. Following the procedure, provide a 95% confidence interval for the mean EAG score of the counselor's clients. 2. You need to calculate an interval of the mean ages of adults of voting age in an electoral district, for this you obtain a random sample of 272 adults of voting age and determine a mean age of 36.3 years with a standard deviation of 9.7 years. Create a 99% confidence interval. 3. The American Restaurant Association collected information on the number of times young married couples eat out each week. A survey of 60 couples indicated that the average number of meals away from home is 2.76 meals per week, with a standard deviation of 0.75, also per week. Construct the 97% confidence interval of the population mean. 4. During a national debate on changes in the healthcare system, a cable news service conducted an opinion poll among 500 small business owners. It was revealed that 65% of these small entrepreneurs do not approve of the changes. Construct the 95% confidence interval of the proportion opposed to such changes in the health system. Discuss the results. 5. Near the time of the election, a cable news service conducts an opinion poll of 1,000 likely voters. The result shows that the Republican contender has an advantage of 52 to 48 percent. a. Construct the 95% confidence interval for the proportion favoring the Republican candidate. b. Find the probability that the Democratic candidate is the actual leader. c. Repeat the above analysis based on a sample of 3,000 likely voters. Consider the following when submitting your test: • Present your answers with the aspects learned so far about parameter estimation and confidence intervals. • Use the APA style manual when submitting your proof in MS Word document.