stat104_lecture22_v1_1up

stat104_lecture22_v1_1up - Stat 104: Quantitative Methods...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Stat 104: Quantitative Methods for Economists Class 22: Hypothesis Testing- Part I (verbage) 1 Hypothesis Testing (intro) We have discussed two methods of making inference on parameters in a population based on a random sample ( in English, how do we figure out the true mean or proportion) Point estimates give us a single guess 2 Confidence intervals give us a region. Alternatively, we might be interested in using the information in a sample to test hypothesis about parameters in the population. A hypothesis (or claim) is simply a belief (usually based on some relevant information). Some examples of a hypothesis might be: What is a hypothesis ? 3 Assigning weekly homework in a statistics class increases scores on course exams. Taking Cold-Eeze reduces the time of your cold The Atkins diet is better than the South Beach diet. b A company that has a 10% market share launches a marketing campaign. At the end of the campaign period the company conducts a survey in order to assess whether its market share has increased. Business Examples 4 b A bottling machine is set to automatically fill each bottle with 355 ml. of soft drink. To check whether the machine needs to be readjusted, a quality control inspector examines a random sample of newly filled bottles. Recap : Confidence Intervals s Allow us to use sample data to estimate a population value, like the true mean or the true proportion, and then put bounds on our estimate. 5 s Example: Give a 95% confidence interval for the true average amount students spend weekly on alcohol. Recap : Hypothesis Testing s Allows us to use sample data to test a claim about a population, such as testing whether a population proportion or population mean equals ome number. 6 some number. s Example: Is the true average amount that students spent weekly on alcohol $20? Parameter Identification s Hypothesis tests can be carried out on all the population parameters (the Greeks), such as the population median or variance. 7 s But in this section, we will conduct tests of hypothesis only regarding the population mean or the population proportion p . Parameter Identification (cont) s In the Market Share example: A company that has a 10% market share launches a marketing campaign. At the end of the campaign period the company conducts a survey in order to assess whether its market share has increased 8 The parameter of interest may be defined as p = the true proportion of customers who would purchase the company's products at the conclusion of the marketing campaign. Parameter Identification (cont) s In the Bottling Machine example: A bottling machine is set to automatically fill each bottle with 355 ml. of soft drink. To check whether the machine needs to be readjusted, a quality control inspector examines a random sample of newly filled bottles....
View Full Document

This note was uploaded on 03/27/2012 for the course STATS 104 taught by Professor Michaelparzen during the Fall '11 term at Harvard.

Page1 / 44

stat104_lecture22_v1_1up - Stat 104: Quantitative Methods...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online