past four weeks‚ I see changes in the process‚ using time as the metric. This paper will display the data that has been collected‚ as well as the calculations for the control limits‚ discuss the effect of the seasonal factors‚ and discuss the confidence intervals and their usefulness. Control Limits Control limits are an easy way to find out if something is statistically wrong with a process. There are upper and lower control limits for every process. If the data in the sample falls outside of either
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Transportation Survey Sample Calculation The confidence interval (also called margin of error) is the plus-or-minus figure usually reported in newspaper or television opinion poll results. For example‚ if you use a confidence interval of 4 and 47% percent of your sample picks an answer you can be "sure" that if you had asked the question of the entire relevant population between 43% (47-4) and 51% (47+4) would have picked that answer. The confidence level tells you how sure you can be. It is expressed
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collected. Managerial Report 1. Use appropriate descriptive statistics to summarize the data on assets and yields for the money market funds. 2. Develop a 95% confidence interval estimate of the mean assets‚ mean 7-day yield‚ and mean 30-day yield for the population of money market funds. Provide a managerial interpretation of each interval estimate. 3. Discuss the implication of your findings in terms of how BIS could use this type of information in preparing their weekly newsletter. Data for
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------------------------------------------------- Chapter 7: 7.11 Suppose that we will randomly select a sample of 64 measurements from a population having a mean equal to 20 and a standard deviation equal to 4. A. Describe the shape of the sampling distribution of the sample mean x. Do we need to make any assumptions about the shape of the population? Why or why not? ------------------------------------------------- This would be a normally distributed bell shaped curve. We do not need
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difference using a 95 percent confidence level. If the sample size is n = 10 from each population‚ the samples are independent‚ and sample standard deviations are used‚ and the variances are assumed equal‚ then the critical value will be t = 2.1009. Answer: TRUE Diff: 2 Keywords: confidence interval‚ mean difference‚ independent‚ sample Section: 10-1 Estimation for Two Population Means Using Independent Samples Outcome: 1 2) To find a confidence interval for the difference between the
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electricity. They want to be 90% confident of their results and want the error of the interval estimate to be no more than $100. They estimate that such bills range from $600 to $2‚500. How large a sample should they take? The margin of error for this confidence interval for the mean is 100=Z*SD/sqrt(n). To solve for N: sqrt N=Z*SD/1.645‚ now square both sides: N=[Z*SD/100]^2 The Z score for a 90% confidence interval is 1.645. The SD standard deviation is 2500-600=1900 1900/4 N=[1.645*(1900/4)/100]^2=62
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Results for the Good Health Survey Florida: Confidence Level at 95% is 1.001191951; Upper Limit is 6.551; Lower Limit is 4.548. The expected value has a 95% chance of being in the confidence range. In the case of the above problem‚ it has a 95% chance of being between 6.551 and 4.548. New York: Confidence Level at 95% is 1.0298559; Upper Limit is 9.0299; Lower Limit is 7.0299. The expected value has a 95% chance of being in the confidence range. In the case of the above problem‚ it has a
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DSC 2008 Business Analytics—Data and Decisions Tutorial 1 This first tutorial is longer than usual‚ because it covers 2 weeks of lecture. Since there are frequently no definitive answers to some parts of tutorial questions‚ please only take these files as containing suggested solutions. Some of you might well have different and better insights. In particular‚ your tutor may have different approaches to some questions. Just as not all decisions in real life are correct‚ not all analytics have
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Marketing Research on Facebook There has been a massive increase in the use of Facebook over the past few years and there is every indication that this will continue. The statistics generated by Facebook are impressive: 219 billion photos shared 2.7 billion ‘Likes’ – EVERY DAY!!! 1.18 trillion “likes 17 billion location check-ins Median age of a Facebook user is 22 years The social network was started by Mark Zuckerberg while he was at University in 2004. This social media website has been
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Reject? We accept a null hypothesis when the significance level greater than .05 Reject when less than .05 Confidence Intervals First you have to know three things: Statistical inference: the process of using sample statistics to estimate population parameters. Confidence level: the probability that a population parameter lies within a given confidence interval Confidence interval: the range of values in which the population parameter is estimated to fall. A statistic is an estimate of
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