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 the non smokers. They have zero cigarettes per day.

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 indepence is people with dementia who smoke twenty or more cigarettes per day.

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

Based on the data smoking does not seem to matter in determining alzheimers. As people who smoke get alzheimers at nearly the same rate as those who dont. Also the pearson residiuals number is 0 meaning they get it at the rate expected.

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)?

Variables that have positive relationship with the number of trail users are: hightemp, avgtemp, lowtemp, and summer.

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

The season that seems to be the most popular for trail users is summer because it has the highest positive correlation out of all the seasons.

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.

There is no relation between these variables because the scatter plot is all over the place. There is no line of best fit for this data.

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.