Motorcycle Accidents. The Scottish Executive, Analytical Services Division Transport Statistics, compiles information on motorcycle accidents in Scotland. During one year, data on the number of motorcycle accidents, by day of the week and type of road (built-up or non–built-up), are as presented on the WeissStats site.

a. Group the bivariate data for these two variables into a contingency table.

b. Determine the conditional distribution of day of the week within each type-of-road category and the marginal distribution of day of the week.

c. Determine the conditional distribution of type of road within each day of the week and the marginal distribution of type of road.

d. Does an association exist between the variables “day of the week”

and “type of road” for these motorcycle accidents? Explain your answer.