Chapter26 - Chapter 26 Comparing Counts Example #3 on p....

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 26 Comparing Counts
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Example #3 on p. 712 After getting trounced by your little brother in a children’s game, you suspect the die he gave to roll may be unfair. To check, you roll it 60 times, recording the number of times each face appears. Do these results (Data on the next slide) cast doubt on the die’s fairness?
Background image of page 2
(cont.) Face Count 1 11 2 7 3 9 4 15 5 12 6 6
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Goodness-of-Fit If the faces were distributed uniformly on each roll, we would expect about 1/6 of them to occur under each face. That suggests 60/6 = 10. How closely do the observed number of faces per roll fit this simple “null” model? A hypothesis test to address this question is called a goodness-of-fit.
Background image of page 4
Test Statistic The test statistic, called the chi-square statistic, is found by adding up the sum of the squares of the deviations between the observed and expected counts divided by the expected counts: - = expected expected) (observed 2 2 χ
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
7.6 10 ) 10 6 ( ... 10
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/16/2011 for the course AMAT 108 taught by Professor Sutphin during the Fall '07 term at SUNY Albany.

Page1 / 14

Chapter26 - Chapter 26 Comparing Counts Example #3 on p....

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online