Quiz 3

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”.

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

The largest group of people with other dimentias is non-smokers. In the graph showed, and the data given, the largest number of people with other dimentias were those who do not smoke every day.

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

It is most surprising that the group of non-smokers contracts the most disease but reading he data again it surprised me more that there were not more disease cases with smokers who smoke more than 20 cigarettes a day. In total there were more cases of disease with smokers who smoked 10-20 cigarettes per day.

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

It does not seem to matter if the majority of those who develop other dimentias are non-smokers.

Q4 Create correlation plot for RailTrail.

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

Q5 List all four variables that have negative correlation with the number of trail users (volume).

The four variables that have negative correlation with the number of trail users are: spring, fal, cloud cover, and precipitation.

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

The season that seems to be the least popular for trail users is fall

Q7 The correlation coefficient between hightemp and cloudcover is quite small. Would you be sure that the two variables are not related at all?

Hint: One word answer (e.g., yes or no) is NOT enough. Explain why.

You can not be entirely certain that something is not related at all but by using the correlation coefficient you can determine the likeliness of it being related. The higher the number, the more likely they are related.

Q7.a Continued from Q7. 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.

According to the scatterplot, you can see that the data is not related. The scatterplot shows data ll over the map and can not see a correlation between the two

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.