On the basis of the duration of an eruption of the Old Faithful geyser, park rangers try to predict the waiting time to the next eruption. In Figure 15.13 a scatterplot is displayed of the duration...

On the basis of the duration of an eruption of the Old Faithful geyser, park rangers try to predict the waiting time to the next eruption. In Figure 15.13 a scatterplot is displayed of the duration and the time to the next eruption in seconds

a. Does the scatterplot give reason to believe that the duration of an eruption influences the time to the next eruption?

b. Suppose you have just observed an eruption that lasted 250 seconds. What would you predict for the time to the next eruption?

c. The dataset of durations shows two modes, i.e., there are two places where the data accumulate (see, for instance, the histogram in Figure 15.1). How many modes does the dataset of waiting times show?