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 other dementias. Discuss it by number of cigarettes per day.

The largest group that has other dementias smokes zero cigarettes a day

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

The one group that has more cases than expected given independence is the dementia group because they smoke more than 20 cigarettes a day

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

Yes, smoking does seem to matter in determining other dementias becuase in the dark shaded blue column, smoking over 20 times a day seems to have an effect on more cases of dementia due to the higher proportion than the rest.

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).

Precipitation, Cloud Cover, Spring and Fall

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

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.

No, I couldnt truly be sure that the variables are not related at all because the weather is unpredictable and although it is -.1, there could still be a linear connection between the two

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.

Yes I would conclude that they are not related due to how spread out the data is on the 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.