Estimate Textbook Costs Fall 09 Blank Template

Estimate Textbook Costs Fall 09 Blank Template - )100% of...

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A repeated sampling experiment to illustrate “Confidence.” Your task is to estimate the population mean textbook expenditures. You will do both point estimation (what formula?) and interval estimation (what formula?). In creating the confidence interval, you can assume you know the true population standard deviation, σ = $146.64 In this experiment, we actually know both the population mean we are trying to predict and the population standard deviation. The experiment should convince you: the sample mean is a random variable (we’ll see a distribution of means from the many different samples); on average, the sample mean will perform well in estimating μ (it’s unbiased ); and some of our confidence intervals will not contain the true mean, but on average, our confidence interval estimates will fall over or contain the true value for about (1-
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Unformatted text preview: )100% of our random samples as predicted by the sampling distribution. This makes sense; we construct our intervals based on the variability in the sampling distributin. To estimate the population mean textbook costs you would draw a random sample; weve done that for you. Your personal sample, one of many, appears in the table below identified by a sample number given in the table. Sample Number X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 i X Determine an 80% confidence interval estimate for the population mean textbook expenses. Provide the lower and upper limits: Lower Limit = Upper Limit = Interpret your confidence interval: What is your point estimate of the population mean? (How do you calculate a point estimate ?) Determine your Sampling Error....
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This note was uploaded on 12/08/2011 for the course ECON 211 taught by Professor Daniellass during the Spring '11 term at UMass (Amherst).

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