Chapter 9.3, Problem 96E

To determine

To explain: Reason that we have convinced that Echinacea helps prevent colds.

Answer to Problem 96E

There is not sufficient evidence to conclude that Echinacea is beneficial and helps prevent colds.

Explanation of Solution

Given information:

  $\alpha =0.05$

Calculation:

There is not sufficient evidence to conclude that Echinacea is beneficial. It is quite likely that the significant results for the three variables occurred by chance.

At the $\alpha =0.05$ level, there is type $I$ error getting a significant result when the null hypothesis is true $5\%$ of the time.

If $50t-$ tests are performed at this significance level and all $50$ null hypotheses were true,so on average $0.05\times 50=2.5$ Type $I$ error.

The three significant results In this situation are quite likely to be such errors.