STAT3175 Linear Models Assignment

Assignment Help Applied Statistics

Reference no: EM132871806

STAT3175 Linear Models - Macquarie University

Instructions
ˆ Complete Assignment 2, using the data sleepdata assn2 2021.csv.

ˆ For all hypothesis tests you should state the null and alternative hypotheses, test statistic, distribution of the test statistic under H0, p-value and conclusion.

Question 1

This question concerns a study conducted on n = 133 patients thought to have the condition Obstructive Sleep Apnea (OSA). These patients have undergone a sleep study at a Canadian sleep clinic.

"Obstructive sleep apnea ... is a breathing disorder characterized by brief interruptions of breathing during sleep. OSA occurs when air cannot flow into or out of the person's nose or mouth although efforts to breathe continue. In OSA, the throat collapses during sleep causing the individual to snort and gasp for breath. Hundreds of these episodes can occur every night."

The purpose of this analysis is to identify the risk factors for OSA. OSA is characterised by the patient frequently waking during the night, measured by the arousal index (number of arousals from sleep per hour of sleep). Potential risk factors for the disease are thought to be obesity, male gender, older age, hypertension (high blood pressure) and consumption of stimulants such as alcohol and caffeine. The variables available for analysis are:

Variable Description

age in years

gender 1=male; 2=female

alcohol usage 0=no; 1=yes
BMI               body mass index
neck size        in cm
SBP               systolic blood pressure (mm Hg)
AI                 arousal index (arousals per hour of sleep)

The data are in the file sleepdata assn2 2021.csv. We will be constructing a regression model with AI (or some transformation thereof) as response variable.

a. Construct histograms of each of the continuous variables, and comment on their shapes.

b. Using either SPSS or ARC, determine which transformation(s), if any, are needed in order to perform the regression. Also decide what to do about any obviously incorrect observations.

c. Construct a scatterplot matrix of the continuous variables (transformed if necessary), and comment on the relationships between the variables.

d. For each of the categorical covariates,

i. examine frequency tables;

ii. examine boxplots of the response against the categorical covariate, and comment on the relationships observed.
e. Construct a statistical model for AI (or a transformed version of it). Write down your final model equation.
f. Perform diagnostic checking, and go back to (e) if necessary.
g. Interpret each of the model coefficients.

h. Write up your results based on this model, in a paragraph suitable to be presented to a clinician. Explain how AI is associated with subjects' characteristics. (This is in addition to your write-up of (a) to (g) above.) Statistical terms and mathematical symbols should be avoided. This paragraph should be at most 100 words.

Question 2

Consider again the data set in Assignment 1. Two other variables given are LeagueIndex and APM (actions per minute). LeagueIndex gives the level of the game coded in increasing order of difficulty as
LeagueIndex Level
1 Bronze
2 Silver
3 Gold
4 Platinum
5 Diamond
6 Master
7 GrandMaster
8 Professional leagues

a. Examine the frequencies of LeagueIndex, and if necessary perform a suitable recoding for inclusion as a covariate. Give the frequencies of your recoded variable.

b. Examine the distribution of APM, and decide on a suitable transformation if necessary.

c. Consider the inclusion of LeagueIndex and APM into the model for log(WorkersMade). You should also consider inclusion of the covariates included in Assignment 1, and inter- action terms. (It is not necessary to perform diagnostic checking.) Write down your final model.

d. Write down the fitted model equations for (i) League Index 2 (Silver), and (ii) League Index 5 (Diamond). Interpret the model coefficients.

e. Compare your final model with the model arrived at in Assignment 1. As a consequence of new information brought into the regression, what information has become redundant?

Attachment:- Linear Models.rar

Reference no: EM132871806

Questions Cloud

How to calculate deferred tax worksheet : Paul Ltd has accrued annual leave entitlements of $1,800 in calculating net profit for the year ended 30 June 2020. How to calculate deferred tax worksheet

Discuss three impacts related to sea level rise : Why are coastal regions important to humans? What is their significance? List and discuss three impacts related to sea level rise.

How is the current government structured in the country : How is the current government structured in this country? How do the structures of government and the other characteristics compare with the characteristics

What collective action problems do see now in american state : What collective action problems do you see now in American state politics? How can the federal government help resolve the problem you've identified?

STAT3175 Linear Models Assignment : STAT3175 Linear Models Assignment Help and Solution, Macquarie University - Assessment Writing Service - Construct histograms of each of the continuous variable

What are the advantages and disadvantages of having state : What are the advantages and disadvantages of having state and local governments take the lead in pandemic prevention policy?

Determine the owners equity : A company has total non-current assets of $70,000, current assets of $30,000, long term liabilities of $40,000. Determine the Owners equity

Assess the coherence of the eu short to medium : Terrorist attacks and the continuing influx of the refugees. Your task is to assess the coherence of the EU's short- to medium-term response to this crisis.

Systematically list processes of coastal erosion : Systematically list the processes of coastal erosion. How does El Nino effect relative sea level along the Pacific Northwest Coast?

User Account

All Pages