Chapter 16 Guiding Questions

Consider the following questions:

1) What is a discrete random variable?

2) What is a continuous random variable?

3) How do you make a probability model for a random variable?

4) What is the expected value of a discrete random variable? How do you calculate the expected value?

5) How do you find the standard deviation of a discrete random variable?

6) What happens to the expected value and variance when...

a) we add or subtract a constant

b) we multiply by a constant

c) we add together two independent random variables

d) we subtract two independent random variables

7) When two independent continuous random variables have Normal models, what is true about the sum or difference of the random variables?

8) Can we add standard deviations together when dealing with random variables?

Comments on the General Addition rule

Actually it works for both, when events are disjoint P(AB)= 0. (in other words since they are disjoint, they don’t overlap so the probability of both A and B happening is zero). And this is the addition rule that works for non-disjoint events, because you have to subtract the overlap, otherwise you are counting that part twice. For example, lets say there are 50 students taking AP stats at East and West. Of those 50 lets define event A as being on an academic team. And event B as being on an athletic team. These events will likely overlap since some people just get involved in everything. For this example lets say there are 20 students out of the 50 on an academic team, 10 on an athletic team, and 4 on both. To determine the probability of being in on an athletic team or an academic team, we need to know the total students on athletic teams or academic teams. So 20 + 10, this could also be written as (16 + 4) + (6 + 4), the 16 are students only on an academic team, the 4 are on both, the 6 are only on an an athletic team the 4 are on both. But the problem is the 4 are the same 4 in each parenthesis. We should not count them twice. So we would do (16+4)+(6+4)-4 or 20+10-4 to get 26 students in athletics or academics, the probability would be 2650= .52 This was done with counts but the same could have been done with percents (.4) + (.2) - .8 = .52.

Chapter 15 Guiding Questions

1) What is the general addition rule for probability? Does this rule work when events are disjoint AND when events are not disjoint?

2) What is conditional probability? What is the formula for conditional probability?

3) What is a contingency table and how can it help us when dealing with probability?

4) How can we mathematically check to see if two events are independent?

5) What is a tree diagram and why do we use these diagrams when dealing with probability?

Ch 14 Day 3

Ch 14 Day 2

Chapter 14 Guiding Questions

1) Define the following: Probability, trial, outcome, event, independent

2) What is the "law of large numbers"?

3) Give some general information about probability. Please mention things like the complement rule, the addition rule, the multiplication rule, and mutually exclusive.

4) What is the difference between mutually exclusive and independence in probability? Can events be both mutually exclusive and independent?

Review Answer Submissions.

There are lots of reasons why we can't do experiments for every situation. If you have taken a psychology or sociology class you may have heard of the Milgram Experiments. Some factors that people are interested in manipulating or testing can cause harm on the participants, which makes them potentially unethical. This is one famous example.

Some survey ideas from Mr. Rossi

1) Cyberbullying/bullying

2) Media and self image

3) Sleep times

4) Extracurricular commitments vs. academics

5) Social network participation

6) Poverty and education (or anything about common distractions at home.)

These next ones are non repeats, but kids would like support.

5) Teaching and humor, does it help in the classroom.

6) Effect of hollywood/disney on attitudes toward romance

7) Attitudes and perspectives of and about Muslims post 9/11

8) Parents adding stress to students by being demanding or strictness/lenience of parents

Chapter 13 Guiding Questions

Here are a few questions to look at for chapter 13.

1) What is an observational study?

2) What is the difference between a retrospective and prospective observational study?

3) What is an experiment?

4) In an experiment, there are a many important things to consider. Please define the following terms: experimental units, factor, response variable, treatments, level, single-blind, double-blind, control group, placebo, matched pair design, statistically significant

5) What are the four principles of experimental design? Describe each principle.

Also please notice the AP Stats Survey Assignment posted in the links section -->

Questions About Sampling Methods

Complete the form found here

Units I & II Review Assignment

In addition to the work you are doing in Unit III, it is important to keep reviewing material from the previous units.

Here is a link to a few review problems that are due on 11/10/11

Unit I & II Review