Introductory Statistics

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IS: R Assignment 23

[<code class="R">R</code> Assignments]
R Assignment #23
 

General Purpose

General Purpose of these Assignments (the usual): The purpose of these R Assignments is to give you some pointed, direct practice in using R. As such, these are designed to be quick and to the point (less than 10 minutes each). They are also designed to give you a place to return if you forget how to perform some analysis in the future.

Please supply your results in the form below. Clicking on “Click to Check Your Answers” will allow you to see which as correct and which are not. When all are correct (and you can try as many time as you wish), you will be allowed to send your answers to me for credit by clicking on “Click to Email Your Results.” You only receive credit when this is submitted (with all answers correct).

This assignment is due at the start of the class period on

Wednesday, February 21, 2024.

With that being said, if this R Assignment is available, which is could be until approximately 11:59 pm (CST), then you are able to work on it.

As expected, these are graded according to the syllabus (all or nothing). Please review the appropriate section in the syllabus for more information. Also, if this is not submitted before it is due, then it counts as a zero.

Specific Purpose: Here, I check that you can calculate p-values for two types of hypothesis tests: a single proportion and comparing two proportions. Remember that these assignments are not here to test some mysterious deeper understanding. They are only here to check that you can perform the analysis.

Slidedeck Support: The following slidedeck may be helpful for you in completing this R Assignment:

The Problems

Note that we are assuming this particular experiment is representative of the entire population (all people). The sample is of 500 people. On each person I measured the eye color and the hair color.

First, run the following code. Then, answer the questions that follow. These lines of code load a particular data set and attaches it. In other words, they allow you easy access to a common data set.

source("http://rfs.kvasaheim.com/stat200.R") dt = read.csv("http://rfs.kvasaheim.com/data/hairandeyecolor.csv") attach(dt)
  1. What is the lower bound on the 95% confidence interval for the proportion of the population that has blue eyes?
  2. What is the upper bound on the 95% confidence interval for the proportion of the population that has blue eyes?
  3. Test the hypothesis that the proportion of brown-haired people who are blue-eyed is the same as the proportion of blonde-haired people who are blue-eyed. Just report the p-value.
    Note that there are two populations to pay attention to. The first is blonde-haired (n=48); the second, brown-haired (n=290).

Finally, to receive credit for this assignment, please provide your full Knox College email address:

then click on the button here.

The Answers

Since this is past due, I can now give you the code and the answer:

Since it is now after the time this is due, I can now give you the code and the answers:

binom.test(x=187,n=500)
binom.test(x=187,n=500)
prop.test(x=c(19,117), n=c(48,290) )

The answers are

0.3314425
0.4180569
1
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