r6 - Math 127B, Basic R, Lecture 6 Mrinal Raghupathi...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Math 127B, Basic R, Lecture 6 Mrinal Raghupathi Wednesday, April 20, 2011 Administrivia Today we will learn how to do a chi-square test in R. Reminders 1. This weeks recitation will again be like a lab for R, in-class. 1 The chi-square test in R The chi-square test is run with the command chisq.test . The command can do all the chi-square tests that we have looked at. This can be done by specifying different options. We will repeat three of the examples from previous classes. The first is rolls of a die. We roll a die 60 times and observe the following frequencies for each face: 11, 13, 15, 10, 9, 2. Create a list of frequencies for the rolls by rolls <- c(11, 13, 15, 10, 9, 2) . The command chisq.test(rolls) will print out the following information > rolls <- c(11, 13, 15, 10, 9, 2) > rolls [1] 11 13 15 10 9 2 > chisq.test(rolls) Chi -squared test for given probabilities data: rolls X-squared = 10, df = 5, p-value = 0.07524 Note the P-value is given as a proportion and not as a percentage. So P = 7 . 524%. Next lets work out the example of the jurors in Alameda county California. Heres the table again. 1 Age County-wide % age Number 21 30 42 5 31 40 23 9 41 60 16 19 61 + 19 33 This time, there is a lot less information. We dont need it. TheThis time, there is a lot less information....
View Full Document

This document was uploaded on 10/29/2011 for the course MATH 127B at Vanderbilt.

Page1 / 4

r6 - Math 127B, Basic R, Lecture 6 Mrinal Raghupathi...

This preview shows document pages 1 - 3. Sign up to view the full document.

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