PO217 Lecture Notes - Lecture 7: Statistical Inference, Confidence Interval, Statistic
Document Summary
Definition: the theoretical, probabilistic distribution of a statistic for all possible samples of a given size (n). The single most important concept in inferential statistics. Every application of inferential statistics involves 3 different distributions: population: empirical; unknown, sampling distribution: theoretical; known, sample: empirical; known. In estimation procedures, statistics calculated from random samples are used to estimate the value of population parameters. Therefore statistics are used to estimate parameters. Two estimation procedures: a point estimate is a sample statistic used to estimate a population value. Example: a newspaper story reports that 15% of a sample of randomly selected. Canadians did not have a regular medical doctor: confidence intervals consist of a range of values. Example: between 12% and 18% of canadians did not have a regular medical doctor. A random sample of 178 canadian households watches tv an average of 6 hours per day, with a standard deviation of 3 (s=3).
