Chapter 4.2, Problem 69E

(a)

To determine

To find out what other variables might be confounded with a doctor’s choice of surgical or non-surgical treatment.

Answer to Problem 69E

The ages of the patient and the health of the patient.

Explanation of Solution

In this study, the researchers study about the effectiveness of the two ways to treat prostate disease by using the records of Canada’s national health care system. The two methods used were traditional surgery and a new method that does not require surgery. In this context, the other variables that might be confounded with a doctor’s choice of surgical or non-surgical treatment are the ages of the patient and the health of the patient. These can also be considered while experimenting the results.

(b)

To determine

To describe a completely randomized design for this experiment.

Explanation of Solution

In this study, the researchers study about the effectiveness of the two ways to treat prostate disease by using the records of Canada’s national health care system. The two methods used were traditional surgery and a new method that does not require surgery.

Thus, we have to randomly assign $300$ students for the experiment who are willing to go through the experiment.

So, it is given there are $300$ patients. Give each patients a unique number from $1\text{ to 300}$ .

We have to randomly assign the subjects to the treatment using randomization method. This can be done as;

Firstly, choose a number. Then, select a first $3$ digit number. If the number is between $001\text{ and 300}$ , then select the corresponding patient for treatment $1$ else move on to next $3$ -digit number. Repeat unit $150$ (unique) patients have been selected for treatment $1$ .

Then the remaining $150$ patients were randomly assigned to the treatment $2$ for the experiment.