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 none smokers is the largest group that has Alzheimers

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

Other dementias that smoke 20 or more cigaretts per day.

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

No smoking does not seem to matter when determining Alzheimers, None smokers is the lagerest seciton with Alzheimers.

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)?

High temp, Average temp, Low temp, Summer

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

Summer is the most popular time for trail users

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.

No correlation, the points are scattered all over the graph.

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.