MATH 124 Lecture Notes - Lecture 17: San Francisco State University, Categorical Variable, Standard Deviation
Document Summary
Lecture 17: a statistician is a number that summarizes the data collected from a sample. There are many different statisticians to summarize data. For example, percentages are used to summarize categorical data and means are used to summarize numerical data. The price of a house is a numerical variable, so you can calculate its mean or standard deviation. In contrast, the color of a house is a categorical variable; there is no point in looking for the standard deviation or the color mean. In this case the important statistics are the percentages of houses of each color: not all statistics are correct or fair, of course. Just because someone gives you a statistic, you have no guarantee that that statistic is scientific or legitimate. You may have heard the saying, "numbers don"t lie, but liars use numbers too. Parameter: the statistics are based on data from a sample, not on population data.
