Chapter 11.4, Problem 4E

To determine

To find: the randomized comparative experiment.

Answer to Problem 4E

The conclusion that milk reduces the chances of having cavities may or may not be valid.

Explanation of Solution

Given:

75 students are monitored for one year who chose milk.

  $75$ students chose other beverages.

  $25\%$ students have fewer cavities who chose milk.

Calculation:

In randomize comparative experiment, subjects are randomly assigned to the control group or the treatment group.

The control group is the group that is subjected to no treatment.

The treatment group is the group that is subjected to the treatment.

The study is not a randomized comparative experiment because the students were not randomly assigned to the control group or the treatment group.

The conclusion that milk reduces the chances of having cavities may or may not be valid. There may be other reasons why students who choose to drink milk over other beverages have fewer cavities. For instance, students who choose milk might also follow other dental hygiene activities like brushing twice a day, using dental floss and follow other healthy eating habits that could be helpful in reducing the chances of having cavities.

Conclusion:

The conclusion that milk reduces the chances of having cavities may or may not be valid.