A researcher is interested in testing the effectiveness of a new stress reductio

Question

A researcher is interested in testing the effectiveness of a new stress reduction method. One randomly selected person is trained in the new method and his stress is measured (low values mean low stress). It is known that the stress level of people in the general population have a mean µ=40 and a standard deviation =10. The score of the subject who received the method was X=25.

1. Complete the steps of hypothesis testing using the p<.05 significance level (alpha). Show each individual step. Given: the cutoff/critical z-value that cuts off the 5% tail of the distribution = -1.64.

2. What do you conclude about the anxiety reducing effectiveness of the method?

3. Did you make a directional or non-directional hypothesis? Explain.

4. Did you do a one-tailed or two-tailed test? Explain.

Explanation / Answer

Lets put out the hypothesis:

H0: Mu < 40

Ha: Mu >= 40

1. First calc. the te statistic = X-Mu / Sigma = (25-40)/10 = -1.5

Now, since our test statistic is more than -1.64 we have the fact that the test statistic is not in the critical range

Hence, we fail to reject Null hypothesis i.e. Pop, mean = 40

2. We conclude that the anxiety reducing effectiveness method has no significant effect on anxeity, i.e. the anxeity continous to be the same even after this treatment

3. It is a directional / 1 tailed hypothesis

4. I did a 1 tailed test as I wanted to check wether my anxeity is lesser than the pop. anxeity of 40. So, there was only 1 tailed involved.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.