Chapter 24, Problem 26E

(a)

To determine

To explain what will you conclude if the P-value is $0.00013$ .

Answer to Problem 26E

There is sufficient evidence to support the claim of improvement.

Explanation of Solution

In the previous question we see that the number of advertised brand names people recalled immediately after watching TV shows or one day later. It appears that they remembered more about the ads the next day. Suppose one analyst conducts a two-sample hypothesis test to see if memory of brands advertised during violent TV shows is higher after one day. The P-value came out be $0.00013$ . So as we know that if the P-value is smaller than the significance level then the null hypothesis is rejected then, we have,

  $P<0.05\Rightarrow \text{Reject }{H}_0$

Thus, there is sufficient evidence to support the claim of improvement.

(b)

To determine

To explain why his procedure was inappropriate and which of the assumptions for inference was violated.

Answer to Problem 26E

The independence assumption is violated.

Explanation of Solution

In the previous question we see that the number of advertised brand names people recalled immediately after watching TV shows or one day later. It appears that they remembered more about the ads the next day. Thus, the procedure was inappropriate because the independence assumption is not satisfied, because the two groups are not independent since they contain the same subjects.

(c)

To determine

To explain how might the design of this experiment have tainted the result.

Explanation of Solution

In the previous question we see that the number of advertised brand names people recalled immediately after watching TV shows or one day later. It appears that they remembered more about the ads the next day. Thus, the design of this experiment might have tainted the result as since the independence assumption was not satisfied, the found significant difference might not be significant at all and thus the result were tainted by exaggerated differences.

(d)

To determine

To suggest a design that could compare immediate brand name recall with recall one day later.

Explanation of Solution

In the previous question we see that the number of advertised brand names people recalled immediately after watching TV shows or one day later. It appears that they remembered more about the ads the next day. Thus, the design that could compare immediate brand name recall with recall one day lateris as first, determine the brand-name recall for each subject immediately after viewing the ads and one day later.Then, determine the paired difference for each of these subjects. And then perform a one-sample t test on the found differences.