Instructions: There are lots of techniques that we can use to try to calm down or relax when we are feeling anxious or tense. One strategy is deep breathing (see this link for some tips on deep breathing, https://www.uofmhealth.org/health-library/uz2255 Links to an external site.). A professor is interested in examining how deep breathing can influence feelings of anxiety. She recruits participants in her class right before the final exam, when their feelings of anxiety would be high. She measures their current levels of anxiety, instructs them to engage in 2 minutes of deep breathing, and then measures their anxiety again after they've completed the breathing. Below are the anxiety levels of each student before and after deep breathing (on a scale from 1 to 30). Your job is to determine if their anxiety levels significantly DECREASE after deep breathing.

Before Deep Breathing	After Deep Breathing
22	20
25	19
15	10
28	12
13	11
16	8
15	10
12	9

1-What's the null hypothesis for this research question?

2-What's the alternative hypothesis for this research question?

3-What's the best statistical test to use to analyze this research question?

One sample z-test

Dependent samples t-test

F statistic

Independent sample t-test

Correlation coefficient

One way ANOVA

4-The next step is to compute the test statistic. What is the t-statistic value (make sure you're using the t-test formula for the dependent samples t-test). Round your answer to two decimal places.

5-What are the degrees of freedom?

6-Should you do a one-tailed or two-tailed test here? Think about whether the hypothesis is directional or non-directional!

7-What is the critical value?

8-Based on the t-value provided and the critical value, what is your decision about this research study?

There is a significant decrease in anxiety after deep breathing

There is not a significant decrease in anxiety before and after deep breathing.

There is a significant increase in anxiety after deep breathing

9-Write up the results. Don't forget to include your means and sds for the before and after data!

*For the next two questions, you're going to design a study that uses a dependent samplest-Test design and a study that uses an independent samplest-Test. Be sure to base your two studies on the same general topic (in other words, apply the same research question to a study where you would use an independent samples t-test design and a study where you would use a dependent samples t test design).

10-What's your independent samples t-test study? Tell me your IV and how you would manipulate the IV, and your DV. This needs to be your own original study idea. It should be very clear why your example is an appropriate example for an independentsamples t-test design.

11-What's your dependent samples t-test study? Tell me your IV and how you would manipulate the IV, and your DV. This needs to be your own original study idea (and it needs to be the same general topic as your independent samples t-test study).It should be very clear why your example is an appropriate example for a dependent samples t-test design.