Exhibit 7-6: A group of researchers hypothesizes that listening to music while studying for an exam influences test scores.They randomly selected 28 subjects and divided them into four groups.All groups studied silently for a test for an hour a day for a week.Group 1 studied without music.Group 2 studied with classical music in the background, Group 3 with country, and Group 4 with jazz.The following are the final test scores:
$\begin{array}{l}
\begin{array}{lll}
\text { Group 1 } & \text { Group 2 } \
50 & 59 \
45 & 57 \
42 & 57 \
41 & 55 \
40 & 56 \
39 & 53 \
38 & 51
\end{array}
\begin{array}{lll}
\text { Group 3} & \text { Group 4 } \

60 & 49 \
56 & 45 \
56 & 45 \
55 & 42 \
54 & 41 \
51 & 39 \
50 & 37
\end{array}
\end{array}$

-Refer to Exhibit 7-6.The researchers can conclude that:
A) Groups 2 and 3 are statistically significantly different from Groups 1 and 4.
B) there is a statistically significant difference among these groups.
C) Groups 2, 3 and 4 are statistically significantly different from the control group.
D) none of these are true.

Question

Exhibit 7-6: A group of researchers hypothesizes that listening to music while studying for an exam influences test scores.They randomly selected 28 subjects and divided them into four groups.All groups studied silently for a test for an hour a day for a week.Group 1 studied without music.Group 2 studied with classical music in the background, Group 3 with country, and Group 4 with jazz.The following are the final test scores:
 $\begin{array}{l}
\begin{array}{lll}
\text { Group 1 } & \text { Group 2 } \
50 & 59 \
45 & 57 \
42 & 57 \
41 & 55 \
40 & 56 \
39 & 53 \
38 & 51
\end{array}
\begin{array}{lll}
\text { Group 3} & \text { Group 4 } \

60 & 49 \
56 & 45 \
56 & 45 \
55 & 42 \
54 & 41 \
51 & 39 \
50 & 37
\end{array}
\end{array}$

-Refer to Exhibit 7-6.The researchers can conclude that:
A) Groups 2 and 3 are statistically significantly different from Groups 1 and 4.
B) there is a statistically significant difference among these groups.
C) Groups 2, 3 and 4 are statistically significantly different from the control group.
D) none of these are true.

Quizplus · Accepted Answer

To determine whether there is a statistically significant difference among the four groups, an analysis of variance (ANOVA) test should be conducted. If the test shows a significant result, then we can conclude that at least one of the groups differs significantly from the others. Therefore, the researchers can conclude that there is a statistically significant difference among these groups. However, we cannot determine which groups are significantly different from each other without further pairwise comparisons.

Exhibit 7-6: a Group of Researchers Hypothesizes That Listening to Music