Chapter 11.6, Problem 5E

To determine

To describe andcorrect: the experimental difference error.

Answer to Problem 5E

It is concludedthe treatment decreases the score.

Explanation of Solution

Given:

  $\begin{array}{l}{\overline{x}}_{treatment}-{\overline{x}}_{control}=16-11\\ =5\end{array}$

Calculation:

In this question you have to describe and correct the error in interpreting the experimental difference of the means.

Experimental difference of the mean is the difference of the mean of treatment group and the mean of the control group.

Thus,

  $\text{Experimental mean }={\overline{x}}_{treatment}-{\overline{x}}_{control}$

So, the error is that the order of subtraction has been reversed in the given calculations.

The correct way is

  $\begin{array}{l}\text{Experimental mean }={\overline{x}}_{treatment}-{\overline{x}}_{control}\\ =11-16\\ =-5\end{array}$

So, it is concluded the treatment decreases the score.

Conclusion:

Therefore,it is concludedthe treatment decreases the score.