Quiz3

The data set is from a case-control study of smoking and Alzheimer’s disease. The data set has two variables of main interest:

• smoking a factor with four levels “None”, “<10”, “10-20”, and “>20” (cigarettes per day)
• disease a factor with three levels “Alzheimer”, “Other dementias”, and “Other diagnoses”.

Q1 Describe the largest group that has Alzheimer. Discuss it by number of cigarettes per day.

The largest group that has Alzheimers is non-smokers because the box is the biggest one out of the mosaic table.

Q2 Describe one group that has more cases than expected given independence (by chance). Discuss it by number of cigarettes per day.

The group that has more cases than expected given independence is the people with other dementias who smoke more than 20 cigarettes per day.

Q3 Does smoking seem to matter in determining Alzheimer? Discuss your reason using the mosaic chart above.

No, smoking does not seem to matter in determining Alzheimer because in the mosaic chart, the boxes for smoking a certain amount of cigarettes per day for Alzheimers is small with no width.

Q4 Create correlation plot for RailTrail.

Hint: The RailTrail data set is from the mosaicData package.

Q5 What variables have positve correlation with the number of trail users (volume)?

The variables that have positive correrlation with the number of trail users is high temp and average temp.

Q6 What season seems to be most popular for trail users?

The season that seems to be most popular for trail users is high temp weather.

Q7 The correlation coefficient between hightemp and cloudcover is quite small. Would you be sure that the two variables are not related at all? Create scatter plot. After examing the scatter plot, would you conclude that the two variables are not related at all?

Hint: Discuss your reason by explaining your scatter plot.

Q8 Hide the messages, the code and its results on the webpage.

Hint: Use message, echo and results in the chunk options. Refer to the RMarkdown Reference Guide.

Q9 Display the title and your name correctly at the top of the webpage.

Q10 Use the correct slug.