STAT 3001 Week 4 Project Assignment 2 (2015)

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Week 4 Project - STAT 3001

Student Name: <Type your name here>

Date: <Enter the date on which you began working on this assignment.>

Instructions: To complete this project, you will need the following materials:

? STATDISK User Manual (found in the classroom in DocSharing)

? Access to the Internet to download the STATDISK program.

Part I. Analyze Data

Instructions Answers

1. Open the file COTININE

using menu option Datasets

and then Elementary Stats,

9

th Edition. This file

contains some information

about a exposure to secondhand

smoke. How many

observations are there in this

file?

In this file, there are three variables, labeled Smokers, ETS, and No ETS. The dataset was collected for

a study of second-hand smoke. The sample data consists of the measured serum cotinine levels in three

different groups of people.

? The NOETS group lists the cotinine levels for subjects who are nonsmokers and have no exposure to

environmental tobacco smoke at home or work.

? The ETS group lists cotinine levels for subjects who are nonsmokers exposed to tobacco smoke at

home or work.

? The SMOKERS group lists cotinine levels for subjects who report tobacco use.

Serum cotinine is a metabolite of nicotine, meaning that cotinine is produced when nicotine is absorbed by

the body. Higher levels of cotinine correspond to higher levels of exposure to smoke that contains nicotine.

2. What results do you expect to

find in this data?

Part II. Descriptive Statistics

3-6Generate descriptive

statistics for all three groups

of people and complete the

following table. Round all

results to 2 decimal places.

Variable Sample

Mean

Sample

Standard

Deviation

Sample Size

Smokers

ETS

2

No ETS

7.Did you get the results you

expected here? Explain why.

8.In which of the three

groups did we experience the

MOST variation (highest

deviation from the mean)?

Part III. Confidence Intervals

9.Generate a 95% interval for

the mean of the SMOKERS

group. Paste your results

here.

10.Generate a 95% interval

for the mean of the ETS

group. Paste your results

here.

11.Generate a 95% interval

for the mean of the No ETS

group. Paste your results here

12.Create a graph below by illustrating all three confidence intervals on one graph using the tools in

your word processor (example below). Statdisk cannot do this for you. Create your graph and turn the

font red. For this process, I just use the dashes and wrote a scale below the axes.

Here is an example, but it is not based on the data you are analyzing:

Case 1 14---------------------42

Case 2 35-------------------------70

________________________________________

0 20 40 60

Your Solution:

13.. Based on the confidence

intervals shown above, does

there appear to be some

evidence to indicate that

exposure to tobacco smoke

corresponds to higher levels of

cotinine?

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Part IV. Hypothesis Testing

14. Let’s say that you are trying to show that the level of cotinine is equal to zero (0) for people who

do not smoke and are not exposed to Environmental Smoke. Compose and test a hypothesis (use

Significance of 0.01) that the cotinine levels are significantly different from 0 for the No ETS group.

Show all steps.

Step 1. Determine parameter of

interest and compose null and

alternative hypotheses.

Step 2. Determine the sample

mean, sample standard deviation,

and sample size. [Hint: You did

this in an above step in this

assignment.]

Step 3. Determine the likelihood

that the population mean is

actually equal to 0 by completing

a Hypothesis Test: One Mean in

STATDISK. Use significance

of 0.01. Paste results here.

Step 4. State your conclusion.

Your conclusion should relate

the p-value and level of

significance to whether you

reject the null hypothesis.

15. Now test the claim of a tobacco company spokesmen that people in the ETS population have

"positive" levels of cotinine (significantly greater than zero), suggesting that this measure is not a

good indicator of exposure to tobacco smoke. Use a significance level of 0.05.

Step 1. Determine parameter of

interest and compose null and

alternative hypotheses.

Step 2. Determine the sample

mean, sample standard deviation,

and sample size. [Hint: You did

this in an above step in this

assignment.]

Step 3. Determine the likelihood

that the population mean is

actually equal to 0 by completing

a Hypothesis Test: One Mean in

STATDISK. Use significance

of 0.05. Paste results here.

Step 4. State your conclusion in

terms of the claim by the tobacco

company.

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16. Answer the following questions based on the above hypothesis test.

a. What is the p-value in

this example and what

does it represent?

b. Given that your data and

p-value do not change,

what would need to be

different in order for us to

FAIL TO REJECT the

null hypothesis here?

Submit your final draft to the Assignment 2 Week 4 area of Turnitin. Please use the naming convention

"WK4Assgn2+first initial+last name" as the Submission Title.