Question

Your statistics professor is involved in another educational outreach program designed to decrease participants’ levels of stress. She designed a study in which participants were randomly assigned to two groups. One group completed a 30-minute meditation. A second, control group watched television for 30-minutes. After 30 minutes, participants reported their level of stress. Your professor, again, asks for your assistance. She predicts that the average level of stress will differ significantly between the meditation and control groups. She wants to use an alpha level of 0.05.

Meditation Group Stress Levels	Television Group Stress Levels
3	5
4	4
2	7
1	6
1	5
2	5
4	3
3	4
2	4
1	5

a. Are you running a one-tailed or two-tailed test?

b. Write your alternative and null hypotheses.

c. Which statistical analysis will you use to run your test (e.g. one-sampled t-test, an independent-samples t-test, a paired t-test, or chi-square test)?

d. Run your statistical analysis using SPSS.

(Remember, if you are running a one-tailed test, your alpha value is located in one-tail, meaning your p-value needs to be less than 0.05 to reject the null

hypothesis.

If you are running a two-tailed test, your alpha value is divided in half,meaning your p-value needs to be less than 0.025 to reject the null

hypothesis)

Answer 1

Sol:

Conduct t test assuming unequal variances

t-Test: Two-Sample Assuming Unequal Variances
	Meditation Group Stress Levels	Television Group Stress Levels
Mean	2.3	4.8
Variance	1.344444	1.288889
Observations	10	10
Hypothesized Mean Difference	0
df	18
t Stat	-4.87177
P(T<=t) one-tail	6.13E-05
t Critical one-tail	1.734064
P(T<=t) two-tail	0.000123
t Critical two-tail	2.100922

a. Are you running a one-tailed or two-tailed test?

two tailed t test

b. Write your alternative and null hypotheses.

:

c. Which statistical analysis will you use to run your test

an independent-samples t-test

Solution-d:

t=

-4.87177

p=0.000123(for two tail)

p<0.05

Reject null hypothesis.

Accept alternative hypothesis.

There is suffcient statistical evidence at 5% level of significance to conlcude that

he average level of stress will differ significantly between the meditation and control groups