Question

The use of a cell phone while driving is often thought to increase the chance of an accident. The dataset reaction.time (UsingR) is simulated data on the time it takes to react to an external event while driving. Subjects with control == ‘C’ are not using a cell phone, and those with control == ‘T’ are. Their time to respond to some external event is recorded in seconds. Create side-by-side boxplots of the variable reaction.time for the two values of control. Compare the centers and spread.

Answer 1

R codes and output:

library(UsingR)
data(reaction.time)
boxplot(time ~ control, data = reaction.time)

We see that median reaction time for control group (C) is less than other group (T).

Also we observe that distribution of control group is positively skewed, it means maximum number of person in this group react very quickly.

Whereas distribution of the other group (control == T) , is negatively skewed,  it means maximum number of person in this group take maximum time to react external events.

The spread of these two distribution is almost same. Because range of these two distribution is approximately same.