A Researcher Wants to Know If Mood Is Affected by Music

Multiple Choice

A researcher wants to know if mood is affected by music. She conducts a test on a sample of 4 randomly selected adults and measures mood rating before and after being exposed to classic rock
Music. Test the hypothesis that mood rating decreased after being exposed to classic rock music.
Following are the mood ratings for the four participants: $\begin{array}{|l|l|l|}\hline & \begin{array}{c}\text { Before } \\\text { exposure }\end{array} & \begin{array}{c}\text { After } \\\text { exposure }\end{array} \\\hline \text { Participant \#1 } & 5.1 & 5.2 \\\hline \text { Participant \#2 } & 4.3 & 4.0 \\\hline \text { Participant \#3 } & 2.5 & 2.5 \\\hline \text { Participant \#4 } & 4.9 & 4.0 \\\hline\end{array}$
Assume that all conditions for testing have been met. Report the null and alternative hypothesis and p-value. At the $5 \%$ significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

A) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$ ; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating.
B) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.015$ ; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating.
C) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$ ; Reject the null hypothesis; there is strong evidence o suggest that exposure to classic rock music decreased mood rating.
D) $\mathrm { H } _ { 0 }$ : $\mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } \neq 0 ; \mathrm { p } = 0.309$ ; Reject the null hypothesis; there is strong evidence to suggest that exposure to classic rock music decreased mood rating.