Understanding Statistics					 J.R. Rasmussen

					Class 11 Outline

I) Today's Class

	A) Turn in assignment 4 extended 
		1) In class Quiz 2 Thursday 2/18/10

	B) Review of assignment 4 extended

	C) Application of Rules 1-4: confidence intervals


II) Go over assignment 4 extended


III) Recap of our last class 

	A) Any open items?

	B) Review of basic rules
		1) random variable X
		2) random sample from X of size n
		3) We look at the mean of the sample: a new random variable
		4) Rule 1 and 2 for the mean and standard deviation of the new variable which is the sampling distribution

	C) The normal distribution
		1) Rule 3
		2) Rule 4  (very, very important)

	D) combining rule 1,2, and 4 into the central limit theorem

	E) We applied to our New York Poll example


IV) BREAK


V) Confidence intervals:  another application of rules 1-4.

	A) Intuitive idea: using a random sample we want to have a method to construct an interval 
	which will represent a range of plausible values for 	the unknown population mean “mu”. 
	We also want to have some way to measure how confident we are of our 	method

	B) Look at standard normal case first with a 95% confidence interval  (draw the picture)

	C) Look at a general normal: mean 3, & standard deviation 2.5

	D) Do example 9.4 pages 380-381

	E) Group exercise
		1) use the Z table to find a 90% area
		2) now apply this 90% z-value to construct a 90% confidence interval for example 9.4

	F) Summarizing what we have done and Rule 3 for the proportion case
		1) the "general" confidence interval formula, page 382

	H) Group exercise: problem 9.12 (b), page 386
			problem 9.18 a, page 387 


VI) Hand out assignment 5 due Tuesday 2/16/10