STAT 100 Lecture Notes - Lecture 10: Normal Distribution, Standard Deviation, Probability Plot

• School: University of Maryland
• Department: Statistics and Probability
• Course: STAT 100
• Professor: Cremins

Document Summary

Always plot your data: make a graph (histogram, stemplot, normal probability plot, box plot, dot plot, etc. ) Look for overall patterns (shape, center, spread) and for striking deviations such as outliers. Calculate a numerical summary to brie y describe center and spread. Sometimes the overall pattern of a large number of observations is so regular that we can describe it by a smooth curve. E(x) - (^) x1p(x - x1) = v(x) - (^) (x1- )^2 p(x=x1) = o(^) If x is continuous then there is a pdf (probability density function) f(x) 0 for all x in domain total area beneath curve of f(x) is 1. 2: p(a x b) = area beneath the curve between a + b. In drawing the normal curve, the mean and the standard deviation have speci c roles: The mean is the center of the curve. The values ( - ) and ( _ ) are the in ection points of the curve.