Probability Question About an “individual” About a “statistic”

Slides:

Advertisements

Similar presentations

THE CENTRAL LIMIT THEOREM

Advertisements

Econ 338/envr 305 clicker questions

Exam One Review Quiz Psy302 Quantitative Methods.

Sampling: Final and Initial Sample Size Determination

EPSY 435 – Educational Statistics EPSY 435 Question – Assignment 10 In the OnLine Testing text area, explain the concept of the sampling distribution of.

Slide 9- 1 Copyright © 2010 Pearson Education, Inc. Active Learning Lecture Slides For use with Classroom Response Systems Business Statistics First Edition.

The Normal Curve Z Scores, T Scores, and Skewness.

Assuming normally distributed data! Naïve Bayes Classifier.

Standard Normal Distribution

Statistical Concepts (continued) Concepts to cover or review today: –Population parameter –Sample statistics –Mean –Standard deviation –Coefficient of.

Chapter 11: Random Sampling and Sampling Distributions

Lesson 12-1 Algebra Check Skills You’ll Need 12-4

Claims about a Population Mean when σ is Known Objective: test a claim.

AP Statistics Chapter 9 Notes.

Understanding the scores from Test 2 In-class exercise.

Measures of Variability Objective: Students should know what a variance and standard deviation are and for what type of data they typically used.

Sampling Distribution of the Sample Mean. Example a Let X denote the lifetime of a battery Suppose the distribution of battery battery lifetimes has 

Chapter 10 – Sampling Distributions Math 22 Introductory Statistics.

The Central Limit Theorem © Christine Crisp “Teach A Level Maths” Statistics 1.

Statistics 300: Elementary Statistics Section 6-5.

6.3 THE CENTRAL LIMIT THEOREM. DISTRIBUTION OF SAMPLE MEANS  A sampling distribution of sample means is a distribution using the means computed from.

Meta-Study. Representation of the Sampling Distribution of Y̅

1 BA 275 Quantitative Business Methods Quiz #2 Sampling Distribution of a Statistic Statistical Inference: Confidence Interval Estimation Introduction.

: An alternative representation of level of significance. - normal distribution applies. - α level of significance (e.g. 5% in two tails) determines the.

Math 4030 – 9b Comparing Two Means 1 Dependent and independent samples Comparing two means.

Chapter 18: The Central Limit Theorem Objective: To apply the Central Limit Theorem to the Normal Model CHS Statistics.

Chapter 18 Sampling Distribution Models *For Means.

Inference ConceptsSlide #1 1-sample Z-test H o :  =  o (where  o = specific value) Statistic: Test Statistic: Assume: –  is known – n is “large” (so.

STA 2023 Section 5.4 Sampling Distributions and the Central Limit Theorem.

INFERENTIAL STATISTICS DOING STATS WITH CONFIDENCE.

1 1 Slide © 2008 Thomson South-Western. All Rights Reserved Chapter 12 Tests of Goodness of Fit and Independence n Goodness of Fit Test: A Multinomial.

Example A population has a mean of 200 and a standard deviation of 50. A random sample of size 100 will be taken and the sample mean x̄ will be used to.

Normal Distributions. Probability density function - the curved line The height of the curve --> density for a particular X Density = relative concentration.

MATH Section 7.2.

Sampling Distribution of the Sample Mean

Central Limit Theorem-CLT

6.39 Day 2: The Central Limit Theorem

Topic 8: Sampling Distributions

Statistical Reasoning for everyday life

STANDARD ERROR OF SAMPLE

Understanding Sampling Distributions: Statistics as Random Variables

Sampling Distributions

Review 49% of all people in the world are male. Interested whether physics majors are more likely to be male than the general population, you survey 10.

Inference: Conclusion with Confidence

Statistical Inference

CHAPTER 10 Estimating with Confidence

Chapter Six Normal Curves and Sampling Probability Distributions

Inferences Based on a Single Sample

Sampling Distributions

Handout THQ #5 at end of class.

Combining Random Variables

Hypothesis Testing: Hypotheses

AP Statistics: Chapter 7

Sampling Distribution of the Sample Mean

Sampling Distribution

Sampling Distribution

Thus we have (Xbar - m )/(s/sqrt(n)) which has a Z distribution if:

SWBAT: Review sampling distributions of sample proportions and means

Lecture Slides Elementary Statistics Twelfth Edition

Sampling Distributions

Sampling Distribution Models

8.3 – Estimating a Population Mean

Quantitative Methods PSY302 Quiz Normal Curve Review February 6, 2017

Suppose that the random variable X has a distribution with a density curve that looks like the following: The sampling distribution of the mean of.

If the question asks: “Find the probability if...”

Example 1: From a random sample of 576 of a company’s employees, it was found that the average number of days each person was absent from work due to illness.

Chapter 6 Confidence Intervals.

Hypothesis Testing for Proportions

Inference Concepts 1-Sample Z-Tests.

CONFIDENCE INTERVALS A confidence interval is an interval in which we are certain to a given probability of the mean lying in that interval. For example.

Presentation transcript:

Probability Question About an “individual” About a “statistic” Use population distribution Use s Must be told if the distribution is normal About a “statistic” Use sampling distribution Use SE CLT tells if normal If the relevant distribution is NOT normal then the probability can NOT be computed. Sampling Distributions

A company is investigating the number of sick days used by each of its employees. Assume that the population is right-skewed with a mean of 7 and a standard deviation of 2 days. What symbol would you put on the 7? What symbol would you put on the 2? m s Sampling Distributions Sampling Distributions Slide #2

A company … population is right-skewed … m=7, s=2 days. For each question determine … Which distribution would be used to answer the question The specifics of that distribution If the question can be answered What is the probability of observing a mean of 6.4 days or less in a random sample of 25 workers? Sampling distribution (about a mean) CLT says … may not be normal, mean=7, SE=2/sqrt(25) Should not (sampling distribution not known to be normal) Sampling Distributions Sampling Distributions Slide #3

A company … population is right-skewed … m=7, s=2 days. For each question determine … Which distribution would be used to answer the question The specifics of that distribution If the question can be answered What is the probability of observing a mean of 6.4 days or less in a random sample of 36 workers? Sampling distribution (about a mean) CLT says …`x~N(7,2/sqrt(36)) Can ... distrib(6.4,mean=7,sd=2/sqrt(36)) Sampling Distributions Sampling Distributions Slide #4

A company … population is right-skewed … m=7, s=2 days. For each question determine … Which distribution would be used to answer the question The specifics of that distribution If the question can be answered What is the probability of observing a worker using fewer than 5 sick days? Population distribution (about an individual) Background says … right-skewed, mean=7, SD=2 NO (population distribution not normal) Sampling Distributions Sampling Distributions Slide #5