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Unformatted text preview: Chapter 6 Section 6.1 1 Chapter 6 Introduction to inference 1. Confidence intervals for estimating the value of a population parameter. the populations parameters is UNKNOWN. <-this will be studied today 1. Tests of significance, which assess the evidence for a claim. A population parameter IS known <- this will be studied next week Chapter 6 Section 6.1 2 Example • Sally works in human resources for a large company. She has been asked to provide her manager with the average number of days that an employee missed over the past year. The company employs thousands of people in 30 different locations. • With help from the HR personnel at the various locations Sally was able to collect data on 50 random employees. She found that the average number of days missed last year was 12.5. She also found a report from the previous year that gave a population standard deviation of 7.8 for days missed. N = 50, x(bar) = 12.5, stand. Dev. = 7.8 you want to use x (bar) to estimate the population mean: where every time to draw a new sample, its...
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- Summer '07
- Normal Distribution, Sally