Question

Questions 9-13 are based on Scenario 3. A researcher is interested in examining whether exposure to “green spaces” (such as those found in nature) can influence stress levels (as measured by cortisol). Researchers place participants in a room lined with green plants for one hour and measure their stress levels before and after being in the room.

Question 9

What is the null hypothesis for scenario 3?

Group of answer choices

H0: µposttest = µpretest

H0: µ1 = µ2 =µ3

H0: r = 0

H0: X = µ

Question 10

What is the alternative hypothesis for scenario 3?

Group of answer choices

H₁: R_xy > 0

H₁: µ1 ≠ µ2 ≠µ3

H₁: X ≠ µ

H₁: µposttest ≠µpretest

Question 11

What is the independent variable for scenario 3?

Group of answer choices

The laboratory

Stress levels

There is no independent variable (because it is a correlational study)

Before and after green space exposure

The participants

Question 12

What is the dependent variable for scenario 3?

Group of answer choices

Before and after green space exposure

The laboratory

Stress levels

The participants

There is no dependent variable (because it is a correlational study)

Question 13

What is the most appropriate test statistic to use to test the hypothesis in scenario 3?

Group of answer choices

regression

correlation coefficient

z-score

dependent samples t test

one way ANOVA

independent samples t-test

z-test

Questions 14-18 are based on Scenario 4. A researcher is interested in studying how exposure to blue spectrum light (the light emitted from smartphones and other technology devices) can influence sleep quality. She randomly assigns one group of participants to use no technology before bed for 1 week, and a second group of participants to look at a smartphone or tablet for 1 hour before bed for 1 week, and a third group to read a book for 1 hour before bed for 1 week. She compares the groups on their sleep quality and expects that the group that uses technology before bed will sleep significantly worse than the other two groups.

Question 14

What is the null hypothesis for scenario 4?

Group of answer choices

H0: µ1 = µ2 =µ3

H0: r = 0

H0: X = µ

H0: µposttest = µpretest

Question 15

What is the alternative hypothesis for scenario 4?

Group of answer choices

H₁: µ1 ≠ µ2 ≠µ3

H₁: R_xy > 0

H₁: X ≠ µ

H₁: µposttest ≠µpretest

Question 16

What is the most appropriate test statistic to use to test the hypothesis in scenario 4?

Group of answer choices

factorial ANOVA

dependent samples t test

independent samples t-test

one way ANOVA

regression

z-score

correlation coefficient

z-test

Question 17

What is the independent variable for scenario 4?

Group of answer choices

Amount of exposure to light (technology) before bed

The amount of time they engage in the bedtime routine (1 hour)

Sleep quality

The length of the study (1 week)

There is no independent variable (because the study is correlational)

Question 18

What is the dependent variable for scenario 4?

Group of answer choices

Amount of exposure to technology before bed

The length of the study (1 week)

There is no dependent variable (because the study is correlational

Sleep quality

The amount of time they engage in the bedtime routine (1 hour)

Questions 19-23 are based on Scenario 5. A researcher is interested in studying whether a company’s sick day policies can influence how much employees feel motivated to work hard. They randomly assign company A to adopt a sick day policy in which employees are given at total of 15 sick days that they may use at any point during the year without question or documentation required, and Company B to adopt a policy in which they are given up to 15 sick days, but they must provide a doctor’s documentation of their illness in order to be able to take the day off. The researcher believes that employees at company A, with the more lenient “no questions asked” policy will feel more motivated to work hard than those at company B, with the stricter sick day policy.

Question 19

What is the alternative hypothesis for scenario 5?

Group of answer choices

H₁: m _CompanyA ≠ m _CompanyB

H₁: µ1 = µ2 =µ3

H₁: r_xy ≠ 0

H₁: m _companyA > m _CompanyB

H₁: m _CompanyA < m _CompanyB

Question 20

What is the independent variable for scenario 5?

Group of answer choices

Employee motivation to work hard

The type of company they work for

The participants

The number of days employees get off each year

There is no independent variable (because it is a correlational study)

Type of sick day policy

Question 21

What is the dependent variable for scenario 5?

Group of answer choices

The type of company they work for

Type of sick day policy

The number of days employees get off each year

Employee motivation to work hard

There is no dependent variable (because it is a correlational study)

Question 22

What is the most appropriate test statistic to use to test the hypothesis in scenario 5?

Group of answer choices

independent samples t-test

z-score

one-way ANOVA

correlation coefficient

dependent samples t-test

z-test

regression

23. Imagine that you actually did the study in scenario 5. Write up the results as you would see it in an APA results section of an empirical article (you can make up the values for your statistical test, means, and standard deviations here).

Answer 1

Scenario 3. Given a researcher is interested in examining whether exposure to green space can influence stress levels. Researchers place participants in a room line with green plants for one hour and measure their stress levels before and after being in the room.

9. Since this is the match paired test, the null hypothesis is:

10. The alternative hypothesis is:

11. The participants are independent of each other. Since the stress level in one participant does not affect on the stress level of other participant.

12. The dependent variable in this study is the stress levels. Since this is the match paired data, the stress level after the exposure to green space depends upon the stress level before the exposure of a participant.

13. The most appropriate test statistic used in this case is: dependent samples t-test.

The test statistic is:

Where d=posttest - pretest