Chapter 4.2, Problem 70E

(a)

To determine

To find out what other variables might be confounded with a mother’s consumption of diet soda during pregnancy.

Answer to Problem 70E

The health of the mother during pregnancy and the nutrients that the mother intake during the period.

Explanation of Solution

In this study, the researchers study about the children of mothers who drank diet soda daily during pregnancy were twice likely to be overweight at age one or not. The study found out that those children were found out to be overweight than those whose mother did not drink diet soda.

In this context, the other variables that might be confounded with a mother’s consumption of diet soda during pregnancy are the health of the mother during pregnancy and the nutrients that the mother intake during the period. As it can be explained as if the mothers were healthy before also so their children will surely found to be healthy.

(b)

To determine

To describe a completely randomized design for this experiment.

Explanation of Solution

In this study, the researchers study about the children of mothers who drank diet soda daily during pregnancy were twice likely to be overweight at age one or not. The study found out that those children were found out to be overweight than those whose mother did not drink diet soda.

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

So, it is given there are $300$ pregnant mothers. 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 pregnant mother fordrinking diet soda else move on to next $3$ -digit number. Repeat unit $150$ (unique) patients have been selected for drinking diet soda for the treatment.

Then the remaining $150$ pregnant motherwere randomly assigned to not drinking of soda for the experiment.