Wisconsin ACT math II This plot shows the mean ACT scores for Wisconsin schools with the Milwaukee schools removed. The vertical lines show the mean, mean - 1s, and mean + 1s. a) Describe the shape of the distribution. b) Does a normal model seem appropriate for this distribution? c) 68.9% of the school average scores are between the two outer lines. Does that support or refute your answer to part b? d) Below, a normal model with mean 21.910 and standard deviation 1.539 is drawn over the histogram. Explain how this demonstrates George Boxs statement, All models are wrongbut some are useful.

Statistics 130M Notes January 19, 2017 notes= January 26, 2017 class Tuesday January 24, 2017 Sick- Skipped Class. Sorry All Thursday January 26, 2017 Chapter 3 Numerical descriptive techniques - Allows us to be precise - Most mathematical calculations Information - When interrupting a histogram we focus on shape Population - Described by parameters - Parameters are often written using greek letters Summaries for symmetric distribution - Central tendency o Balancing point/ halfway point o ***should be same**** o Average of mean o Center of symmetric distribution Skewed distribution - Extreme values/ outliers effected the average - Curve killer - Don’t use balancing point Arithmetic mean