Hypothesis Tests for Population Means Section 10-4.

Slides:

Advertisements

Similar presentations

You will need Your text Your calculator And the handout “Steps In Hypothesis Testing” Bluman, Chapter 81.

Advertisements

Chapter 8 Hypothesis Test.

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

Confidence Intervals with Means Chapter 9. What is the purpose of a confidence interval? To estimate an unknown population parameter.

Confidence Intervals Chapter 7. Rate your confidence Guess my mom’s age within 10 years? –within 5 years? –within 1 year? Shooting a basketball.

Confidence Intervals Chapter 10. Rate your confidence Name my age within 10 years? 0 within 5 years? 0 within 1 year? 0 Shooting a basketball.

Two Population Means Hypothesis Testing and Confidence Intervals With Known Standard Deviations.

© McGraw-Hill, Bluman, 5th ed., Chapter 8

Testing the Difference Between Means (Small Independent Samples)

AP Statistics: Chapter 23

Section 8.2 Z Test for the Mean.

Confidence Intervals Chapter 10. Rate your confidence Name my age within 10 years? within 5 years? within 1 year? Shooting a basketball at a wading.

Significance Tests for Proportions Presentation 9.2.

Find the mean number of points for the basketball team and the standard deviation. PlayerPointsSt. Dev. John51 Tim82 Ed124.

Worksheet for Hypothesis Tests for Means

Chapter 10 Section 2 Z Test for Mean 1.

INFERENCE ABOUT MEANS Chapter 23. CLT!! If our data come from a simple random sample (SRS) and the sample size is sufficiently large, then we know the.

© McGraw-Hill, Bluman, 5th ed., Chapter 8

8.2 z Test for a Mean S.D known

+ The Practice of Statistics, 4 th edition – For AP* STARNES, YATES, MOORE Chapter 9: Testing a Claim Section 9.3a Tests About a Population Mean.

Student’s t-distributions. Student’s t-Model: Family of distributions similar to the Normal model but changes based on degrees-of- freedom. Degrees-of-freedom.

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.

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.

Chapter 23 Inference for One- Sample Means. Steps for doing a confidence interval: 1)State the parameter 2)Conditions 1) The sample should be chosen randomly.

8.1 Testing the Difference Between Means (Independent Samples,  1 and  2 Known) Key Concepts: –Dependent vs Independent Samples –Sampling Distribution.

Unit 8 Section 8-3 – Day : P-Value Method for Hypothesis Testing  Instead of giving an α value, some statistical situations might alternatively.

Aim: How do we use a t-test?

Lesson Testing Claims about a Population Mean in Practice.

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.

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

Estimating a Population Mean. Student’s t-Distribution.

Confidence Intervals for a Population Mean, Standard Deviation Unknown.

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

Aim: What is the P-value method for hypothesis testing? Quiz Friday.

Assumptions and Conditions –Randomization Condition: The data arise from a random sample or suitably randomized experiment. Randomly sampled data (particularly.

Warm Up For a sample of size 23 with an area to the right=.05, what would the t value be? 90% confidence with n=24. What would the t value be? If df=19.

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.

Unit 8 Section : Hypothesis Testing for the Mean (σ unknown)  The hypothesis test for a mean when the population standard deviation is unknown.

Hypothesis Testing. Terminology Hypothesis Testing: A decision making process for evaluating claims about a population. Every situation begins with a.

Warm Up Researches tested 150 farm raised salmon for organic contaminants. They found the mean of the carcinogenic insecticide mirex to be.0913 parts per.

Confidence Intervals with Means Chapter 9. What is the purpose of a confidence interval? To estimate an unknown population parameter.

Independent Samples: Comparing Means Lecture 39 Section 11.4 Fri, Apr 1, 2005.

Chapter 9 Hypothesis Testing

Hypothesis Tests Large Sample Mean

Topic 20 Examples Check of Answers.

Unit 8 Section 7.5.

Testing the Difference between Means and Variances

Properties of Normal Distributions

Hypothesis Tests One Sample Means

Math 4030 – 10a Tests for Population Mean(s)

Hypothesis Tests Small Sample Mean

Chapter 9 Hypothesis Testing

Hypothesis Testing C H A P T E R E I G H T

Independent Samples: Comparing Means

Hypothesis Tests One Sample Means

Independent Samples: Comparing Means

Confidence intervals for the difference between two means: Paired samples Section 10.3.

Chapter 9 Hypothesis Testing

Hypothesis Testing for means

Hypothesis Tests for a Standard Deviation

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 and Confidence Intervals

Day 60 Agenda: Quiz 10.2 & before lunch.

Independent Samples: Comparing Means

Presentation transcript:

Hypothesis Tests for Population Means Section 10-4

Warm-Up

Remember: Sampling Distribution of Means Approximately Normal If population is normal If n  30 (CLT)

Use the z Test Statistic if is known and it’s a large sample Assumptions: 1. SRS 2. Approx Normal – since n> 30 or pop is normal 3. Independent (10 * n)

If population standard deviation is unknown or n<30: Use T-Distribution Use tcdf (beginning, end, df)

Assumptions SRS Approximately Normal  n< 30: Use t unless there are outliers or the data is really skewed.  n  30: Use t (if  is unknown), data can be skewed  Use boxplots to check for skewness Independent

A researcher reports that the average salary of assistant professors is more than $42,000. A sample of 30 assistant professors has a mean salary of $43,260. At = 0.05, test the claim that assistant professors earn more than $42,000 a year. The standard deviation is $5,230.

A national magazine claims the average student watches less tv than the general public. The national average is 29.4 hours with a standard deviation of 2 hours. In a sample of 30, the mean is 27 hours. Using a confidence level of 0.01, is there enough evidence to support their claim?

The average salary for nurses is $24,000. A sample of 10 nurses has a mean of $23,450 and a standard deviation of $400. Is this really the mean salary. Use = 0.05.

A machine is designed to fill jars with 16 ounces of coffee. A consumer suspects that the machine is not filling the jars completely. They sampled 12 jars shown below. Is there enough evidence to support the consumer’s claim at = 0.10?

The Medical Rehabilitation 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 large hospital, a researcher selected a random sample of 35 stroke victims and found that the average cost of their rehabilitation if $25,266. The st. dev. Is $3,251. At = 0.01, can it be concluded that the average cost at a large hospital is different?

A researcher wishes to test the claim that the average age of lifeguards is Ocean City is greater than 24 years. She selects a sample of 36 guards and finds the mean of the sample to be 24.7, with a st. dev. Of 2 years. Is there evidence to support the claim at = 0.05?

A physician claims that jogger’s maximal volume oxygen uptake is greater than the average of all adults. A sample of 15 joggers has a mean of 43.6 ml per kg and a standard deviation of 6 ml/kg. If the average of all adults is 36.7 ml/kg, is there enough evidence to support the physician’s claim at = 0.01?