1. What are the mean and median ages?
2. Plot a histogram of the distribution of the ages. Using this plot and the information from #1, determine if the age variable is normally distributed, positively skewed, or negatively skewed.
3. What is the mean percentage of time that the participants in this study spend traveling on public transportation during inclement weather?
4. What is the standard deviation of Pubtran?
5. What is the correlation between age and how often the person chooses to drive in inclement weather? Is this correlation statistically significant at the .01 level? Are older people more or less likely to report that they drive in inclement weather?
6. Compute a 95% confidence interval on the correlation between age and how often the person chooses to drive in inclement weather.
7. Is there a gender difference in the likelihood to drive in inclement weather? Do the following exercises to find out.
a. Plot side-by-side (parallel) box plots of Cho2drive by gender.
b. What is the mean difference in how much men and women choose to drive in inclement weather?
c. Perform an independent samples t test.
d. Is there any evidence that the assumption of homogeneity of variance is violated?
e. What is the 95% confidence interval for the mean difference?
f. Can you reject the null hypothesis if α = .05?
8. What is the correlation between how often a person chooses to drive in inclement weather and the percentage of accidents the person believes occur in inclement weather? Is this correlation significantly different from 0?
9. What is the correlation between how often someone rides public transportation in inclement weather (Pubtran) and what percentage of accidents the person thinks occur in inclement weather (Accident)?
10. Use linear regression to predict how often someone rides public transportation in inclement weather from what percentage of accidents that person thinks occur in inclement weather. (Pubtran by Accident)
a. Comment on possible assumption violations for the test of the slope.