Understanding Statistics					 J.R. Rasmussen

					Class 6 Outline

0) Hand back assignment1:  GOOD JOB 	!!

I) Last Class

	A) Any open items or questions?


II) Today's Class:

	A) Topics to be covered
		1) binomial distribution
		2) mean of a probability distribution
		3) variance/standard deviation of a probability distribution
		4) Homework working session


III) Summary of what we covered last class

	A) introduction to probability distributions
		1) Binomial distribution
			a) example of 4 emergency calls with Pr(Med) = .85
			b) tree of outcomes

	B) group exercise: birth of girls 
		1) Pr(success)=Pr(girl)=.49
		2) A family has three children
		3) we found the Pr(exactly one girl) during our last class
		4) we found the Pr(exactly 2 girls)
 		4) Use of Excel
		5) we constructed  the the table of values and probabilities
  		(the formal name for the table is probability distribution)

	C) general formula:  formalize our work of last time (pg. 732)

IV) Probability continued

	A) Random variables and probability distributions
		1) why we are looking at these concepts (inference)
		2) previous examples in new "language"
			a) heights of students in class
			b) toss two dice: sum on dice
			c) toss a coin, the number of heads 
			d) length of time a light bulb burns
			e) amount of red blood cells in blood
			f) number of girls in a family of 3 children
		3) discrete and continuous
			a) count/measure

	B) Mean and variance of a probability distribution (on handout)
		1) why we need:  "real world" vs "theoretical world"
		2) Intuitive idea of what we are trying to do
		2) Definition of the mean "mu"
		3) examples: do girls example
		4) Definition of variance and standard deviation "sigma"
		5) example 6.9 page 269
			i) group exercise: calculate the two means
			ii) I calculate the two variances

Break	


V) Assignment 3 working session

	A) Problems on means and variances of probability distributions
		1) definition of mean of a probability distribution
		2 problem 6.20(a), page 271 of hand out:  I do
		3) group problem: problem 6.20(b) of hand out
		4) how to set up on Excel
		6) group exercise: problem 6.26, page 272 of hand out

	B) Problems on binomial distribution
		1) problem A2, page 736:  I do part (a)
		2) group problem:  part (b) of problem A2
		3) problem A2 on Excel


VI) Quiz 1 will be take home, handed out on Wednesday 2/1 and due on Monday 2/6;  
Assignment 3 will be due on Wednesday 2/1.