Student s t Distribution Robb T Koether Homework Review Student s t Distribution Introduction Lecture 34 Section 10 2 TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment Robb T Koether Hampden Sydney College Fri Oct 30 2009 Outline Student s t Distribution 1 Homework Review 2 Introduction 3 TI 83 Data Option 4 Student s t Distribution 5 Degrees of Freedom t Probabilities 6 t Probabilities Hypothesis Testing Unknown 7 Hypothesis Testing Unknown 8 Assignment Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom Assignment Outline Student s t Distribution 1 Homework Review 2 Introduction 3 TI 83 Data Option 4 Student s t Distribution 5 Degrees of Freedom t Probabilities 6 t Probabilities Hypothesis Testing Unknown 7 Hypothesis Testing Unknown 8 Assignment Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom Assignment Homework Review Student s t Distribution Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Exercise 10 4 page 633 A psychologist is studying the distribution of IQ scores of girls at an alternative high school She wants to test the hypothesis that the average IQ score is 100 against the alternative that it is higher than 100 She assumes that the normal distribution with standard deviation 15 is a good model for these IQ scores Hypothesis Testing Unknown She takes a random sample of nine girls from this high school and measures their IQ Assignment The average IQ score for these nine girls was 114 Homework Review Student s t Distribution Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment Exercise 10 4 page 633 Assuming that the appropriate assumptions are met compute the test statistic and p value for this test State your decision at level 0 01 and write up your conclusion in words Homework Review Student s t Distribution Robb T Koether Homework Review Solution Let s just show all seven steps Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom 1 The hypotheses are H0 100 H1 100 2 0 01 t Probabilities Hypothesis Testing Unknown Assignment 3 The test statistic is z x 0 n Homework Review Student s t Distribution Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment Solution 4 Compute z 114 100 15 9 14 5 2 8 5 The p value is normalcdf 2 8 E99 0 0026 6 Reject H0 7 The average IQ score of the girls at the alternative high school is higher than 100 Outline Student s t Distribution 1 Homework Review 2 Introduction 3 TI 83 Data Option 4 Student s t Distribution 5 Degrees of Freedom t Probabilities 6 t Probabilities Hypothesis Testing Unknown 7 Hypothesis Testing Unknown 8 Assignment Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom Assignment Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Introduction Student s t Distribution Robb T Koether Homework Review Last time we made a very important but unrealistic assumption The value of was known Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment What happens if is not known We have to use s as an approximate the value of Does that have any ramifications Yes But first let s do the Z test on the TI 83 using the data option Outline Student s t Distribution 1 Homework Review 2 Introduction 3 TI 83 Data Option 4 Student s t Distribution 5 Degrees of Freedom t Probabilities 6 t Probabilities Hypothesis Testing Unknown 7 Hypothesis Testing Unknown 8 Assignment Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom Assignment Example The Data Option Student s t Distribution Robb T Koether Homework Review Introduction TI 83 Data Option Student s t Distribution Degrees of Freedom t Probabilities Hypothesis Testing Unknown Assignment Example TI 83 Data Option A large number
View Full Document
Unlocking...