solution

You may have heard someone say that drinking coffee will
stunt your growth. To test this, college students were asked their heights and
if they were coffee drinkers. The data fi le CoffeeHeight.txt has the results.
Copy and paste this data set into the Descriptive Statistics applet.

 a. Based on just how the distributions look, do you think
there is an association between height and drinking coffee? Is so, in what way?
Explain.

b. Notice there are two peaks (or what is called bimodal) in
the distribution of heights for the non–coffee drinkers? Why do you think the
distribution has this feature?

 c. Find the mean height for the coffee drinkers and the
non–coffee drinkers. With this added information, do you think there is an
association between drinking coffee and height? Explain.

 d. Find the median height for the coffee drinkers and the
non–coffee drinkers. With this added information, do you think there is an
association between drinking coffee and height? Explain.

 e. If you could find that coffee drinkers were
significantly shorter than non–coffee drinkers in a study like this, would this
show there is a tendency for coffee to stunt a person’s growth? Explain.