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 Alzheimer’s is the group that smokes no cigarettes per day. You can tell by looking at the graph and the largest box is the ones that do not smoke.

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 would be other dimentias (only bos with blue) with more than 20 cigarettes a day.

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

Smoking does not seem to be a determining factor in having Alzheimer because the largest group of people in the mosaic plot were the non-smokers. If smoking was a determining factor in having Alzeihmer’s, more people who smoke cigarettes would have Alzheimer’s.

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)?

Four variables in the correlation plot have a positive correlation with the amount of trail users or “volume”. They are hightemp, lowtemp, avgtemp, summer because they have positive numbers above .0.

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

The correlation plot shows that the most popular season for the trail users is summer.Summer, out of all the seasons, has the highest correlation for volume at .23.

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.

The scatterplot shows that the two variables, hightemp and cloudcover, have no non linear relationship and have no relationship at all. We can tell from the scartterplot because the dots are all over the place and not in a linear direction.

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.