Homework Assignment Chapter 1, Problems 6, 15 Chapter 2, Problems 6, 8, 9, 12 Chapter 3, Problems 4, 6, 15 Chapter 4, Problem 16 Due a week from Friday:

Slides:



Advertisements
Similar presentations
Probability.
Advertisements

CHAPTER 40 Probability.
1-1 Copyright © 2015, 2010, 2007 Pearson Education, Inc. Chapter 13, Slide 1 Chapter 13 From Randomness to Probability.
Copyright © 2010, 2007, 2004 Pearson Education, Inc. Chapter 14 From Randomness to Probability.
Introduction to Probability Experiments, Outcomes, Events and Sample Spaces What is probability? Basic Rules of Probability Probabilities of Compound Events.
Probability Distributions CSLU 2850.Lo1 Spring 2008 Cameron McInally Fordham University May contain work from the Creative Commons.
Chapter 8: Estimating with Confidence
Sampling: Final and Initial Sample Size Determination
Probability Simple Events
Chapter 4 Probability and Probability Distributions
Unit 4 Sections 4-1 & & 4-2: Sample Spaces and Probability  Probability – the chance of an event occurring.  Probability event – a chance process.
Section 5.1 Constructing Models of Random Behavior.
1 Chapter 6: Probability— The Study of Randomness 6.1The Idea of Probability 6.2Probability Models 6.3General Probability Rules.
1 Business Statistics - QBM117 Assigning probabilities to events.
Probability.
MA 102 Statistical Controversies Monday, April 1, 2002 Today: Randomness and probability Probability models and rules Reading (for Wednesday): Chapter.
Sampling Distributions
2-1 Sample Spaces and Events Conducting an experiment, in day-to-day repetitions of the measurement the results can differ slightly because of small.
Proportions. First, some more probability! Why were there so many birthday pairs? 14 people 91 pairs.
Applying the ideas: Probability
Probability (cont.). Assigning Probabilities A probability is a value between 0 and 1 and is written either as a fraction or as a proportion. For the.
Chapter 4 Basic Probability
Copyright © 2010, 2007, 2004 Pearson Education, Inc. Chapter 14 From Randomness to Probability.
Standard error of estimate & Confidence interval.
CHAPTER 5 PROBABILITY. CARDS & DICE BLACKRED CLUBSPADEDIAMONDHEARTTOTAL ACE11114 FACE CARD (K, Q, J) NUMBERED CARD (1-9) TOTAL13 52.
Chapter 15: Probability Rules!
Basic Probability (Chapter 2, W.J.Decoursey, 2003) Objectives: -Define probability and its relationship to relative frequency of an event. -Learn the basic.
Special Topics. Definitions Random (not haphazard): A phenomenon or trial is said to be random if individual outcomes are uncertain but the long-term.
Review of normal distribution. Exercise Solution.
Chapter 9 Introducing Probability - A bridge from Descriptive Statistics to Inferential Statistics.
5.1 Basic Probability Ideas
Statistics 303 Chapter 4 and 1.3 Probability. The probability of an outcome is the proportion of times the outcome would occur if we repeated the procedure.
Population All members of a set which have a given characteristic. Population Data Data associated with a certain population. Population Parameter A measure.
1-1 Copyright © 2015, 2010, 2007 Pearson Education, Inc. Chapter 13, Slide 1 Chapter 13 From Randomness to Probability.
1  Event - any collection of results or outcomes from some procedure  Simple event - any outcome or event that cannot be broken down into simpler components.
CHAPTER 5 Probability: Review of Basic Concepts
Using Probability and Discrete Probability Distributions
AP Statistics Chapter 6 Notes. Probability Terms Random: Individual outcomes are uncertain, but there is a predictable distribution of outcomes in the.
Summary -1 Chapters 2-6 of DeCoursey. Basic Probability (Chapter 2, W.J.Decoursey, 2003) Objectives: -Define probability and its relationship to relative.
Week 21 Conditional Probability Idea – have performed a chance experiment but don’t know the outcome (ω), but have some partial information (event A) about.
Copyright © 2010 Pearson Education, Inc. Chapter 14 From Randomness to Probability.
+ The Practice of Statistics, 4 th edition – For AP* STARNES, YATES, MOORE Unit 5: Estimating with Confidence Section 10.1 Confidence Intervals: The Basics.
Fitting probability models to frequency data. Review - proportions Data: discrete nominal variable with two states (“success” and “failure”) You can do.
Copyright © 2010 Pearson Education, Inc. Chapter 6 Probability.
Slide 5-1 Chapter 5 Probability and Random Variables.
Lesson Probability Rules. Objectives Understand the rules of probabilities Compute and interpret probabilities using the empirical method Compute.
PROBABILITY, PROBABILITY RULES, AND CONDITIONAL PROBABILITY
From Randomness to Probability Chapter 14. Dealing with Random Phenomena A random phenomenon is a situation in which we know what outcomes could happen,
POSC 202A: Lecture 4 Probability. We begin with the basics of probability and then move on to expected value. Understanding probability is important because.
1 1 Slide © 2007 Thomson South-Western. All Rights Reserved Chapter 4 Introduction to Probability Experiments, Counting Rules, and Assigning Probabilities.
YMS Chapter 6 Probability: Foundations for Inference 6.1 – The Idea of Probability.
How likely is it that…..?. The Law of Large Numbers says that the more times you repeat an experiment the closer the relative frequency of an event will.
Inference: Probabilities and Distributions Feb , 2012.
Review Normal Distributions –Draw a picture. –Convert to standard normal (if necessary) –Use the binomial tables to look up the value. –In the case of.
Probability. What is probability? Probability discusses the likelihood or chance of something happening. For instance, -- the probability of it raining.
+ Chapter 5 Overview 5.1 Introducing Probability 5.2 Combining Events 5.3 Conditional Probability 5.4 Counting Methods 1.
Week 21 Rules of Probability for all Corollary: The probability of the union of any two events A and B is Proof: … If then, Proof:
Chapter 14 From Randomness to Probability. Dealing with Random Phenomena A random phenomenon: if we know what outcomes could happen, but not which particular.
Chapter 6 - Probability Math 22 Introductory Statistics.
Probability Models Section 6.2. The Language of Probability What is random? What is random? Empirical means that it is based on observation rather than.
WARM UP: Penny Sampling 1.) Take a look at the graphs that you made yesterday. What are some intuitive takeaways just from looking at the graphs?
Feb. 23 Statistic for the day: Estimated market value of usable body parts of an adult human: $46,000,000 Source: Harper’s index Assignment: Read Chapter.
AP Statistics From Randomness to Probability Chapter 14.
Review Day 2 May 4 th Probability Events are independent if the outcome of one event does not influence the outcome of any other event Events are.
Conditional Probability 423/what-is-your-favorite-data-analysis-cartoon 1.
Probability and Probability Distributions. Probability Concepts Probability: –We now assume the population parameters are known and calculate the chances.
Chapter 6 6.1/6.2 Probability Probability is the branch of mathematics that describes the pattern of chance outcomes.
What is Probability? Quantification of uncertainty.
Honors Statistics From Randomness to Probability
Unit 6: Application of Probability
Presentation transcript:

Homework Assignment Chapter 1, Problems 6, 15 Chapter 2, Problems 6, 8, 9, 12 Chapter 3, Problems 4, 6, 15 Chapter 4, Problem 16 Due a week from Friday: Sept. 22, 12 noon. Your TA will tell you where to hand these in

Random Sampling - what did we learn? It’s difficult to do properly Why not just point? Computers and random numbers Can you tell if your numbers were random?

Sampling distribution of the mean

How confident can we be about this one estimate of the mean?

Estimating error of the mean Hard method: take a few MORE random samples, and get more estimates for the mean Easy method: use the formula:

Confidence interval –a range of values surrounding the sample estimate that is likely to contain the population parameter We are 95% confident that the true mean lies in this interval

 = 5.14 Y = 5.26

What if we calculate 95% confidence intervals? Approximately ± 2 S.E. Expect that 95% of the intervals from the class will contain the true population mean, invervals * 5% = 3.5 Expect that 3 or 4 will not contain the mean, and the rest will

Mean ± 95% C.I.

What if we took larger samples? Say, n=20 instead of n=10?

Probability

The Birthday Challenge

Probability The proportion of times the event occurs if we repeat a random trial over and over again under the same conditions Pr[A] –The probability of event A

(cannot both occur simultaneously)

Mutually exclusive

Venn diagram

Mutually exclusive Venn diagram Sample space

Mutually exclusive Venn diagram Sample space Possible outcome Pr[B] proportional to area

Mutually exclusive

Pr(A and B) = 0

Mutually exclusive Visual definition - areas do not overlap in Venn diagram

Not mutually exclusive Pr(A and B)  0 Pr(purple AND square)  0

For example

Probability distribution

Random variable - a measurement that changes from one observation to the next because of chance

Probability distribution for the outcome of a roll of a die Number rolled Frequency

Probability distribution for the sum of a roll of two dice Sum of two dice Frequency

The addition rule

Addition Rule Pr[1 or 2] = ?

Addition Rule Pr[1 or 2] = Pr[1]+Pr[2]

Addition Rule Pr[1 or 2] = Pr[1]+Pr[2]

Addition Rule Pr[1 or 2] = Pr[1]+Pr[2] Sum of areas

The probability of a range For families of 8 children, Pr[Number of boys ≥ 6] = ?

The probability of a range For families of 8 children, Pr[Number of boys ≥ 6] = Pr[6 or 7 or 8] = Pr[6]+Pr[7]+Pr[8]

The probabilities of all possibilities add to 1.

Addition Rule Pr[1 or 2 or 3 or 4 or 5 or 6] = ?

Addition Rule Pr[1 or 2 or 3 or 4 or 5 or 6] = 1

Probability of Not Pr[NOT rolling a 2] = ?

Probability of Not Pr[NOT rolling a 2] = 1 - Pr[2] = 5/6

Probability of Not Pr[NOT rolling a 2] = 1 - Pr[2] = 5/6 Pr[not A] = 1-Pr[A]

The addition rule

What if they are not mutually exclusive?

General Addition Rule A B Pr[A or B] = ?

General Addition Rule A B Pr[A or B] = ? A B

General Addition Rule A B Pr[A or B] = ? A B

General Addition Rule A B Pr[A or B] = ? A B

General Addition Rule A B A B

Pr[Walks or flies] = ?

General Addition Rule Pr[Walks or flies] = ?

General Addition Rule Pr[Walks or Flies] = Pr[Walks] + Pr[Flies] - Pr[Walks and Flies]

General Addition Rule

Independence

Equivalent definition: The occurrence of one does not change the probability that the second will occur

Multiplication rule If two events A and B are independent, then Pr[A and B] = Pr[A] x Pr[B]

Pr[boy]=0.512

General Addition Rule

Multiplication rule If two events A and B are independent, then Pr[A and B] = Pr[A] x Pr[B]

OR versus AND OR statements: –Involve addition –It matters if the events are mutually exclusive AND statements: –Involve multiplication –It matters if the events are independent

Probability trees

Sex of two children family

Dependent events Variables are not always independent; in fact they are often not

Fig wasps

Testing independence Are the previous state of the fig and the sex of an egg laid independent? Test the multiplication rule: Pr[A and B] ?=? Pr[A] x Pr[B] Pr[fig already has eggs and male] ?=? P[fig already has eggs] x Pr[male]

Conditional probability Pr[X|Y]

Law of total probability:

The general multiplication rule

Does not require independence between A and B

Bayes' theorem

In class exercise

Answer

Homework Assignment Chapter 1, Problems 6, 15 Chapter 2, Problems 6, 8, 9, 12 Chapter 3, Problems 4, 6, 15 Chapter 4, Problem 16 Due a week from Friday: Sept. 22, 12 noon. Your TA will tell you where to hand these in