PADP 7120 Lecture Notes - Lecture 4: Statistical Parameter, Unimodality, Point Estimation

• School: University of Georgia
• Department: Public Administration and Policy
• Course: PADP 7120
• Professor: Anastasopoulos

Document Summary

As one variable increases, the other decreases (2) positive, linear association. As one variable increases, the other increases (3) no association. Dot plots: useful for visualizing numerous observations on one numerical variable & for making observations of the distribution of the data (i. e. center, shape, & spread, darker dots = more observations, dot plots & mean. Sample mean (sample statistic) measures the center of a data set"s distribution. Serves as a point estimate of the population mean. Population mean (population parameter) often not able to calculate because a population"s data is not always available. Right skewed > more rare units on the right. Left skewed > more rare units on the left. Symmetric > highest frequency is in the center: variance. Roughly the average squared deviation from the mean: standard deviation. Square root of variance: q1, q3, & iqr illustrated by box plot. Median > 50th percentile (midpoint of data)