Section 8.2 Z Test for the Mean.

Slides:



Advertisements
Similar presentations
You will need Your text Your calculator
Advertisements

8.2 cont. p-Value Method.
8.3 T- TEST FOR A MEAN. T- TEST The t test is a statistical test for the mean of a population and is used when the population is normally or approximately.
© McGraw-Hill, Bluman, 5th ed., Chapter 8
Business Statistics - QBM117 Testing hypotheses about a population proportion.
© McGraw-Hill, Bluman, 5th ed., Chapter 9
© McGraw-Hill, Bluman, 5th ed., Chapter 8
Unit 8 Section 8-6.
BCOR 1020 Business Statistics Lecture 20 – April 3, 2008.
An importer of Herbs and Spices claims that average weight of packets of Saffron is 20 grams. However packets are actually filled to an average weight,
Worksheet for Hypothesis Tests for Means
Aim: How do we test a comparison group? Exam Tomorrow.
Chapter 10 Section 2 Z Test for Mean 1.
Section 9.5 Testing the Difference Between Two Variances Bluman, Chapter 91.
© McGraw-Hill, Bluman, 5th ed., Chapter 8
8.2 z Test for a Mean S.D known
Chapter 9 Testing the Difference Between Two Means, Two Proportions, and Two Variances Copyright © 2012 The McGraw-Hill Companies, Inc. Permission required.
Testing the Difference Between Two Means: Dependent Samples
Chapter 10 Section 3 Hypothesis Testing t test for a mean.
Unit 8 Section : z Test for a Mean  Many hypotheses are tested using the generalized statistical formula: Test value = (Observed Value)-(expected.
Chapter 9 Section 2 Testing the Difference Between Two Means: t Test 1.
INTRODUCTION TO INFERENCE BPS - 5th Ed. Chapter 14 1.
State the null and alternative hypotheses in the following case: a)Experiments on learning in animals sometimes measure how long it takes a mouse to find.
STEP BY STEP Critical Value Approach to Hypothesis Testing 1- State H o and H 1 2- Choose level of significance, α Choose the sample size, n 3- Determine.
Other Chi-Square Tests
Section 9.3 ~ Hypothesis Tests for Population Proportions Introduction to Probability and Statistics Ms. Young.
Hypothesis Tests for Population Means Section 10-4.
Testing the Difference Between Two Means: Dependent Samples Sec 9.3 Bluman, Chapter 91.
Section 8.3 Testing the Difference Between Means (Dependent Samples)
Chapter 9.  Many instances when researchers wish to compare two sample means  Examples: ◦ Average lifetimes of two different brands of bus tires ◦ Two.
Aim: How do we test hypotheses that compare means of two groups? HW: complete last two questions on homework slides.
9.2 Testing the Difference Between Two Means: Using the t Test
Unit 8 Section 8-3 – Day : P-Value Method for Hypothesis Testing  Instead of giving an α value, some statistical situations might alternatively.
11.5 Testing the Difference Between Two Variances
Aim: How do we use a t-test?
Exercise - 1 A package-filling process at a Cement company fills bags of cement to an average weight of µ but µ changes from time to time. The standard.
© The McGraw-Hill Companies, Inc., Chapter 10 Testing the Difference between Means, Variances, and Proportions.
Sec 8.5 Test for a Variance or a Standard Deviation Bluman, Chapter 81.
McGraw-Hill, Bluman, 7th ed., Chapter 12
Aim: What is the P-value method for hypothesis testing? Quiz Friday.
Doing the Right Thing! … statistically speaking...
While you wait: Please enter the following data on your calculator. Before Data in one list, the After data in a different list. Bluman, Chapter 91.
© The McGraw-Hill Companies, Inc., Chapter 9 Testing the Difference between Two Means.
Sullivan – Fundamentals of Statistics – 2 nd Edition – Chapter 11 Section 3 – Slide 1 of 27 Chapter 11 Section 3 Inference about Two Population Proportions.
Chapter 8 Hypothesis Testing © McGraw-Hill, Bluman, 5th ed., Chapter 8 1.
You will need Your text t distribution table Your calculator And the handout “Steps In Hypothesis Testing” Bluman, Chapter 81.
Hypothesis Testing Chapter 8.
Welcome to MM207 Unit 7 Seminar Dr. Bob Hypothesis Testing and Excel 1.
Chapter 10 Section 5 Chi-squared Test for a Variance or Standard Deviation.
Hypothesis Testing with TWO Samples. Section 8.1.
1 Section 8.4 Testing a claim about a mean (σ known) Objective For a population with mean µ (with σ known), use a sample (with a sample mean) to test a.
A telephone company representative estimates that 40% of its customers have call-waiting service. To test this hypothesis, she selected a sample of 100.
Chapter 9 Hypothesis Testing
Testing the Difference between Means, Variances, and Proportions
Hypothesis Tests Large Sample Mean
Unit 8 Section 7.5.
Testing the Difference Between Two Means
Testing the Difference between Means and Variances
Chapter 9 Testing the Difference Between Two Means, Two Proportions, and Two Variances.
Chapter 5 STATISTICS (PART 3).
Testing the Difference Between Two Means: Dependent Samples
Hypothesis Testing C H A P T E R E I G H T
Testing the Difference Between Two Variances
Elementary Statistics: Picturing The World
Do Now Take out review so I can come check
Exercise - 1 A package-filling process at a Cement company fills bags of cement to an average weight of µ but µ changes from time to time. The standard.
Hypothesis Testing for Proportions
Additional Topics Regarding Hypothesis Testing
Use invNorm (2nd VARS 3) functions: Use invT (2nd VARS 4) functions:
Presentation transcript:

Section 8.2 Z Test for the Mean

z Test for a Mean where = sample mean μ = hypothesized population mean  = population standard deviation n = sample size

A researcher wishes to see if the mean number of days that a basic, low-price, small automobile sits on a dealer’s lot is 29. A sample of 30 automobile dealers has a mean of 30.1 days for basic, low-price, small automobiles. At α = 0.05, test the claim that the mean time is greater than 29 days. The standard deviation of the population is 3.8 days.

Step 1 State the hypotheses and identify the claim. Step 2 Find the critical value. Since α = 0.05 and the test is a right-tailed test, the critical value is z = +1.65. Step 3 Compute the test value.

Step 4 Make the decision. Step 5 Summarize the results. There is not enough evidence to support the claim that the mean time is greater than 29 days.

A researcher claims that the average cost of men’s athletic shoes is less than $80. He selects a random sample of 36 pairs of shoes from a catalog and finds the average to be 75. Is there enough evidence to support the researcher’s claim at α = 0.10? Assume  = 19.2.

The Medical Rehabilitation Education Foundation reports that the average cost of rehabilitation for stroke victims is $24,672. To see if the average cost of rehabilitation is different at a particular hospital, a researcher selects a random sample of 35 stroke victims at the hospital and finds that the average cost of their rehabilitation is $26,343. The standard deviation of the population is $3251. At α = 0.01, can it be concluded that the average cost of stroke rehabilitation at a particular hospital is different from $24,672?