Understanding Statistics					 J.R. Rasmussen

					Class 3 Outline

I) Last Class

	A) Any open items or questions?


II) Homework

	A) Class turn in assignment 1

	B) Go over homework


III) Summary of what we have covered

	A) Data
		1) categorical
		2) numerical
			a) discrete
			b) continuous

	B) Samples and population

	C) Histograms
		1) frequency
		2) relative frequency
		3) how to construct on Excel

	D) Summary statistics
		1) averages
		2) median, and other quartiles
		3) standard deviation
		4) how to calculate on Excel


IV) Break	


V) Introduction to statistical inference

	A) General concept
		1) We want to move from the known sample to the unknown population
		2) our height data for the class and all UWB heights

	B) Variability of samples

		1) Need to understand if we are going to be able to infer 	
		from the sample to the population
		2) Role of probability
			a) Probability is the means to measure the variability 
			of results of experiments
			
	C) Examples of variability of results
		1) Group exercise:  group of four flipping a coin
			a) have groups of four flip four coins
			b) what would the guess be for the frequency from 	
			their results
			c) record results on the board

		2) Student Web visits:  exploring the variability of the average
			a) example 4.3, page 143
			b) students load the data onto Excel
			c) discuss how we draw a sample on Excel
			d) each pair of students draw a sample of size 10 from our population
			e) calculate the average of the sample
			f) record results on the board
			g) compare the sample results with the actual average


VI) Homework

	A) Hand out homework assignment 2 due Wednesday 10/14/09

	B) Homework working session
		1) start with the review problems