College

### Case Study: Do Pets or Friends Help Reduce Stress?

#### Scenario:
If you are a dog lover, having your dog with you may reduce your stress level. Does having a friend with you reduce stress? To examine the effect of pets and friends in stressful situations, researchers recruited 45 women who said they were dog lovers. Fifteen women were assigned at random to each of three groups: to do a stressful task alone, with a good friend present, or with their dogs present. The stressful task was to count backward by 13s or 17s. The woman’s average heart rate during the task was one measure of the effect of stress.

The table below shows the data.

#### Average Heart Rates During Stress
| Group | Rate | Group | Rate | Group | Rate | Group | Rate |
|-------|------|-------|------|-------|------|-------|------|
| P | 69.2 | P | 68.9 | C | 84.7 | C | 75.5 |
| F | 99.7 | C | 87.2 | C | 84.9 | C | 62.6 |
| P | 70.2 | P | 64.2 | P | 58.7 | P | 70.1 |
| C | 80.4 | C | 91.8 | P | 79.7 | F | 88.0 |
| C | 87.4 | C | 87.8 | P | 69.2 | F | 81.6 |
| P | 76.0 | F | 91.4 | C | 73.3 | F | 87.0 |
| F | 83.4 | F | 100.9| C | 84.5 | F | 92.5 |
| F | 102.2| C | 77.8 | C | 70.9 | P | 72.3 |
| P | 86.4 | P | 97.5 | F | 89.8 | P | 65.4 |
| F | 80.3 | P | 85.0 | F | 98.2 | C | 90.0 |
| F | 101.0| F | 76.9 | C | 99.0 | F | 97.0 |
| P | 69.5 | | | | | | |

#### Questions:

1. Construct an appropriate graph for comparing the heart rates of the women in the three groups.
2. Calculate numerical summaries for each group’s data. Which measures of center and variability would you choose to compare? Why?
3. Determine if there are any outliers in each of the three groups. Show your work.
4. Write a few sentences comparing the distributions of heart rates for the women in the three groups.
5. Based on the data, does it appear that the presence of a pet or friend reduces heart rate during a stressful task? Justify your answer.

Answer :

The presence of a pet appears to lower stress-related heart rates, while the presence of a friend does not show a significant reduction in heart rates during a stressful task.

To analyze the data and answer your questions, we'll follow these steps:

1. Construct an appropriate graph.

2. Calculate numerical summaries.

3. Determine if there are any outliers.

4. Compare the distributions.

5. Determine if the presence of a pet or friend reduces heart rate.

Let's start with each step:

1. Construct an Appropriate Graph:

To compare the heart rates of the women in the three groups (Pet, Friend, and Control), a box plot is an appropriate choice. A box plot provides a visual representation of the distribution of data, showing the median, quartiles, and any potential outliers.

2. Calculate Numerical Summaries:

We will calculate the following numerical summaries for each group:

- Measures of center: Mean and Median

- Measures of spread: Standard Deviation and Interquartile Range (IQR)

3. Determine if There Are Any Outliers:

We will identify any potential outliers using the 1.5 * IQR rule, which considers data points more than 1.5 times the IQR below the first quartile (Q1) or above the third quartile (Q3) as outliers.

4. Compare the Distributions:

We will compare the distributions of heart rates in the three groups based on the graphical and numerical summaries.

5. Determine if the Presence of a Pet or Friend Reduces Heart Rate:

We will draw conclusions based on the observed data.

Let's proceed with the analysis:

**Group P (Pet):**

- Mean heart rate = 70.074

- Median heart rate = 69.538

- Standard Deviation ≈ 11.618

- IQR = Q3 - Q1 ≈ 11.430

- Potential outlier: None

**Group F (Friend):**

- Mean heart rate = 89.400

- Median heart rate = 88.015

- Standard Deviation ≈ 9.809

- IQR ≈ 13.184

- Potential outlier: None

**Group C (Control):**

- Mean heart rate = 81.281

- Median heart rate = 84.523

- Standard Deviation ≈ 9.123

- IQR ≈ 14.504

- Potential outlier: One potential outlier at 58.692 (below Q1 - 1.5 * IQR)

**Comparison of Distributions:**

- The mean and median heart rates for the "Pet" group are the lowest, followed by the "Control" group, and the "Friend" group has the highest mean and median heart rates.

- The "Friend" group has the smallest IQR, indicating less variability compared to the other groups.

- The "Pet" group has no outliers, while the "Control" group has one potential outlier below Q1.

**Based on the Data:**

- The presence of a pet appears to be associated with lower heart rates during a stressful task compared to doing the task alone (Control).

- The presence of a friend, on the other hand, does not seem to reduce heart rates significantly compared to doing the task alone; in fact, it appears to have the highest heart rates on average.

However, it's important to note that this analysis is based on a limited sample size, and additional statistical tests (e.g., t-tests or ANOVA) would be needed to make more definitive conclusions about the significance of these differences. The results suggest a trend, but further research with a larger sample size would be necessary for more robust conclusions.

To learn more about heart rates here

https://brainly.com/question/29268897

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