Topic 21—Comparison of Proportions Example. Test of Significance A test of significance for the difference of two proportions Requirements: – Indep. SRS.

Slides:

Advertisements

Similar presentations

Advertisements

AP Statistics Section 11.2 B. A 95% confidence interval captures the true value of in 95% of all samples. If we are 95% confident that the true lies in.

Ch. 21 Practice.

12.1 Inference for A Population Proportion.  Calculate and analyze a one proportion z-test in order to generalize about an unknown population proportion.

Comparing Two Proportions

Two Sample Hypothesis Testing for Proportions

Section 7.1 Hypothesis Testing: Hypothesis: Null Hypothesis (H 0 ): Alternative Hypothesis (H 1 ): a statistical analysis used to decide which of two competing.

Hypothesis Testing Steps of a Statistical Significance Test. 1. Assumptions Type of data, form of population, method of sampling, sample size.

Stat 217 – Day 21 Cautions/Limitations with Inference Procedures.

Inference (CI / Tests) for Comparing 2 Proportions.

Inferences about two proportions Assumptions 1.We have proportions from two simple random samples that are independent (not paired) 2.For both samples,

WARM – UP ( just do “a.” ) The Gallup Poll asked a random sample of 1785 adults, “Did you attend church or synagogue in the last 7 days?” Of the respondents,

Chapter 25 Asking and Answering Questions About the Difference Between Two Population Means: Paired Samples.

BCOR 1020 Business Statistics Lecture 18 – March 20, 2008.

Statistics Testing the Difference Between Proportions Statistics Mrs. Spitz Spring 2009.

Statistical Inference Dr. Mona Hassan Ahmed Prof. of Biostatistics HIPH, Alexandria University.

One Sample  M ean μ, Variance σ 2, Proportion π Two Samples  M eans, Variances, Proportions μ1 vs. μ2 σ12 vs. σ22 π1 vs. π Multiple.

Warm-up Day of 8.1 and 8.2 Quiz and Types of Errors Notes.

CHAPTER 21: Comparing Two Proportions

Section 10.1 ~ t Distribution for Inferences about a Mean Introduction to Probability and Statistics Ms. Young.

Comparing Two Proportions

Section 9.2 Testing the Mean  9.2 / 1. Testing the Mean  When  is Known Let x be the appropriate random variable. Obtain a simple random sample (of.

STA291 Statistical Methods Lecture 24. Comparing Two Proportions Sample of 25, year-olds: Men: 84.9% diploma rate Women: 88.1% diploma rate Are.

Significance Toolbox 1) Identify the population of interest (What is the topic of discussion?) and parameter (mean, standard deviation, probability) you.

Chapter 10 Inferences from Two Samples

Tests About a Population Proportion

The Practice of Statistics Third Edition Chapter 13: Comparing Two Population Parameters Copyright © 2008 by W. H. Freeman & Company Daniel S. Yates.

Warm-up Day of 8.1 and 8.2 Review. 8.2 P#20, 23 and 24 P#20 a. and b. c. Since the p-hat is along the line for reasonably likely events.

AP Statistics Chapter 22 Notes “Comparing Two Proportions”

Confidence Intervals and Tests of Proportions. Assumptions for inference when using sample proportions: We will develop a short list of assumptions for.

Testing Hypothesis That Data Fit a Given Probability Distribution Problem: We have a sample of size n. Determine if the data fits a probability distribution.

Statistics 101 Chapter 10 Section 2. How to run a significance test Step 1: Identify the population of interest and the parameter you want to draw conclusions.

12.2 (13.2) Comparing Two Proportions. The Sampling Distribution of.

Section A Confidence Interval for the Difference of Two Proportions Objectives: 1.To find the mean and standard error of the sampling distribution.

Slide Slide 1 Section 8-4 Testing a Claim About a Mean:  Known.

One sample Tests & Intervals on the Calculator. The ages of a group of volunteers were: 27, 16, 9, 14, 32, 15, 16, 13. The manager wants to show that.

Brailyn Robertson & Rebecca Shigo. DQ Background The Beginning : 1930’s First sold during a trial run at a friend's ice cream store in cents,

2 sample interval proportions sample Shown with two examples.

1 Chapter 9: Introduction to Inference. 2 Thumbtack Activity Toss your thumbtack in the air and record whether it lands either point up (U) or point down.

Section 11.3: Large-Sample Inferences Concerning a Difference Between Two Population or Treatment Proportions.

12.1 Inference for A Population Proportion.  Calculate and analyze a one proportion z-test in order to generalize about an unknown population proportion.

Hypothesis Testing Errors. Hypothesis Testing Suppose we believe the average systolic blood pressure of healthy adults is normally distributed with mean.

AP Statistics Unit 5 Addie Lunn, Taylor Lyon, Caroline Resetar.

© The McGraw-Hill Companies, Inc., Chapter 10 Testing the Difference between Means, Variances, and Proportions.

Lecture PowerPoint Slides Basic Practice of Statistics 7 th Edition.

Statistical Inference Drawing conclusions (“to infer”) about a population based upon data from a sample. Drawing conclusions (“to infer”) about a population.

AP Process Test of Significance for Population Proportion.

1 Hypothesis Tests on the Mean H 0 :  =  0 H 1 :    0.

Lesson Use and Abuse of Tests. Knowledge Objectives Distinguish between statistical significance and practical importance Identify the advantages.

Comparing Two Proportions. AP Statistics Chap 13-2 Two Population Proportions The point estimate for the difference is p 1 – p 2 Population proportions.

By.  Are the proportions of colors of each M&M stated by the M&M company true proportions?

Introduction to Inference Tests of Significance. Wording of conclusion revisit If I believe the statistic is just too extreme and unusual (P-value < 

Hypothesis Tests Hypothesis Tests Large Sample 1- Proportion z-test.

Comparing Two Proportions Chapter 21. In a two-sample problem, we want to compare two populations or the responses to two treatments based on two independent.

Significance Test for the Difference of Two Proportions

One-Sample Inference for Proportions

Comparing Two Proportions

STAT 312 Chapter 7 - Statistical Intervals Based on a Single Sample

Topic 21—Comparison of Proportions

Chapter Review Problems

Hypothesis Test for Independent Groups Two Proportions

CHAPTER 6 Statistical Inference & Hypothesis Testing

CHAPTER 12 Inference for Proportions

CHAPTER 12 Inference for Proportions

Sample Mean Compared to a Given Population Mean

Sample Mean Compared to a Given Population Mean

Interpreting Computer Output

Chapter 8 Inferences from Two Samples

Presentation transcript:

Topic 21—Comparison of Proportions Example

Test of Significance A test of significance for the difference of two proportions Requirements: – Indep. SRS or Random assign. to groups? Randomly assigned to groups—OK –. – Results should be valid

Ho: Pa = Pp The proportion of all HIV+ people who develop AIDS on AZT equals proportion of HIV+ people who develop AIDS on placebo Ha: Pa < Pp The proportion of all HIV+ people who develop AIDS on AZT is less than the proportion of HIV+ people who develop AIDS on placebo Z = P(z< ) =.0017

Because our p-value is less than 5%, we reject the null hypothesis. We have enough evidence to conclude that the proportion of HIV+ people who develop AIDS on AZT is less than the proportion of HIV+ people who develop AIDS on a placebo.

Confidence Interval 95% confidence interval to estimate the difference between 2 proportions Requirements – Same as above..

(-.0805, ) I am 95% confident that the true difference between the proportions who developed AIDS between the AZT and placebo groups is between and ***AZT group developed AIDS between 1.6% and 8% less often.