Let\'s say you decided to investigate the impact of Justin Bieber\'s music on ag
ID: 3060360 • Letter: L
Question
Let's say you decided to investigate the impact of Justin Bieber's music on aggression levels in males. For the aggression questionnaire that you chose, the population mean is 35. After placing 16 males in a room, retrofitted with massive speakers, you play the song "Love Yourself" on repeat, for 2 hours. After two (2) hours, you give these 16 men the aggression questionnaire. They score a mean of 56 with an estimated standard deviation of 10. Calculate the appropriate test statistic. Your answer should only include the numerical value, rounded to the hundredths place. For example, "7.54". You only have two possibilities: a t-test or a z-test
Based on your findings in question #23, would you reject or fail to reject the null hypothesis that males would not be more aggressive after listening to Justin Bieber? In your answer, please include what your critical value was and whether it was a one-tailed or two-tailed test.
Explanation / Answer
mean is X¯=56 and standard deviation is s=10, and sample size is n = 16.
(1) Null and Alternative Hypotheses
The following null and alternative hypotheses need to be tested:
Ho: = 35
Ha: < 35
This corresponds to a left-tailed test, for which a t-test for one mean.
(2) Rejection Region
Taking significance level is =0.05, and the critical value for a left-tailed test is tc=1.753.
The rejection region for this left-tailed test is R = {t: t < -1.753}
(3) Test Statistics
The t-statistic is computed as follows:
t = [ (X¯0) / (s/n) ] = [ (5635) / (10/16) ] = 8.4
(4) Decision about the null hypothesis
Since it is observed that t=8.4 tc=1.753, it is then concluded that the null hypothesis is not rejected.
Using the P-value approach: The p-value is p = 1, and since p=10.05, it is concluded that the null hypothesis is not rejected.
(5) Conclusion
It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the population mean is less than 35, at the 0.05 significance level.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.