Chapter 11.2, Problem 37E

(a)

To determine

To summarize these data in a two-way table.

Explanation of Solution

In the question, it is given different ways so that a person can quit smoking and the table with different ways and with their success. Thus, the summary of these data in a two-way table can be represented as:

  

(b)

To determine

To make a graph to compare the success rates for the four treatments and describe what you see.

Explanation of Solution

In the question, it is given different ways so that a person can quit smoking and the table with different ways and with their success. And the proportion in each group is the number of successes/failures divided by the row total given in the last column is as:

  

Thus, the graph to compare the success rates for the four treatments can be constructed as:

  

Thus, by looking at the histogram we can say that there appears to be no different in proportion between Nicotine Patch and Placebo. And the group Drug or Both seem to have a better success rate.

(c)

To determine

To explain in words what the null hypothesis $H_0:p_1=p_2=p_3=p_4$ says about subjects’ smoking habits.

Answer to Problem 37E

It says proportion of successes for each treatment is the same.

Explanation of Solution

In the question, it is given different ways so that a person can quit smoking and the table with different ways and with their success. Thus, it is given the null hypothesis in the question as:

  $H_0:p_1=p_2=p_3=p_4$

And the null hypothesis says about the subjects’ smoking habits that this means that the proportion of successes for each treatment is the same.

(d)

To determine

To find the expected counts if null hypothesis is true and display them in a two-way table of observed counts.

Explanation of Solution

In the question, it is given different ways so that a person can quit smoking and the table with different ways and with their success. Thus, it is given the null hypothesis in the question as:

  $H_0:p_1=p_2=p_3=p_4$

And the summary of these data in a two-way table can be represented as:

  

Thus, the expected counts are the row total multiplied by the column total, divided by the sample size $n=893$ as: