This preview shows pages 1–8. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: STATISTICAL INFERENCE STATISTICAL INFERENCE Example Example A large utility company has 650,000 residential customers. Annually, a sample of 400 customers is selected to measure customer satisfaction. Customers rate satisfaction as either satisfied or unsatisfied . The company wants to know what proportion of the 650,000 customers are satisfied . Definitions Definitions Population A set of items that one wants to investigate Example: All 650,000 residential customers Variable Information of interest about each item in the population Example: Satisfaction ( satisfied or unsatisfied ) Parameter Numerical quantity that describes a characteristic of a population Unknown unless every item in the population is measured Parameters are represented with symbols, e.g., p  population proportion  population average The symbol is the Greek letter mu. Review Example Review Example In our example, we might define p = proportion of customers in the population of 650,000 customers who are satisfied . Sample A subset of items selected from a...
View
Full
Document
This note was uploaded on 03/16/2009 for the course ECN 221 taught by Professor Roberts during the Spring '07 term at ASU.
 Spring '07
 Roberts
 Utility

Click to edit the document details