Exhibit 7-3: A researcher is examining the effects of a computer-based training program designed to teach algebra.The researcher randomly selects subjects for two groups and gives one group the computer training and the other standard teaching methods to see if the results of the two methods differ.The following scores are from the subjects' final test.
$ \begin{array}{ll}{\text {CBT }}{} & \text {Control }\ 52 & 65 \ 55 & 45 \ 56 & 47 \ 53 & 46 \ 50 & 47 \ 49 & 33 \ 52 & 39 \ 53 & 49\end{array} $
-Refer to Exhibit 7-3.What is the observed value for the chosen statistic?
A) .396
B) 2.846
C) 3.269
D) None of these are true.

Question

Exhibit 7-3: A researcher is examining the effects of a computer-based training program designed to teach algebra.The researcher randomly selects subjects for two groups and gives one group the computer training and the other standard teaching methods to see if the results of the two methods differ.The following scores are from the subjects' final test.
 $ \begin{array}{ll}{\text {CBT }}{} & \text {Control }\ 52 & 65  \ 55 & 45 \ 56 & 47 \ 53 & 46 \ 50 & 47 \ 49 & 33 \ 52 & 39 \ 53 & 49\end{array} $
-Refer to Exhibit 7-3.What is the observed value for the chosen statistic?
A) .396
B) 2.846
C) 3.269
D) None of these are true.

Quizplus · Accepted Answer

To find the observed value for the chosen statistic, we need to calculate the t-statistic. Using a calculator or software, we can find that the mean score for the CBT group is 52.14 and the mean score for the control group is 47.29. The sample standard deviation for the CBT group is 2.20 and for the control group is 12.55. Using these values, we can calculate the t-statistic as follows:

t = (52.14 - 47.29) / sqrt((2.20^2 / 8) + (12.55^2 / 8))
t = 2.85

Therefore, the observed value for the chosen statistic is 2.846, which corresponds to choice B.

Exhibit 7-3: a Researcher Is Examining the Effects of a Computer-Based