MATH 225 Week 5 Assignment: Lab

Student Name
Chamberlain University
MATH-225 Statistical Reasoning for the Health Sciences
Prof. Name
Date
Week 5 Lab Assignment
Height Data Collection and Sampling Method
For this study, data was gathered regarding the height of ten female acquaintances. The information was collected informally through verbal responses rather than physical measurements, which introduces potential inaccuracies. The method employed to gather this data is classified as a convenience sampling technique, where participants were readily accessible and willingly provided their self-reported heights via a group text message. This approach, while practical, increases the likelihood of bias and reduces the overall validity of the results. The potential for error is further heightened due to subjective responses like, “I think I’m around 5’6” or “last time I checked I was 5’4”. Such approximations diminish the precision of the data set.
Raw Height Data
The collected height data (in inches) is listed below:
| Participant | Height (in inches) |
|---|---|
| 1 | 64 |
| 2 | 64 |
| 3 | 65 |
| 4 | 65 |
| 5 | 66 |
| 6 | 66 |
| 7 | 66 |
| 8 | 67 |
| 9 | 67 |
| 10 | 69 |
Descriptive Statistics
Using Excel to analyze the sample, the following descriptive statistics were calculated:
| Statistical Measure | Value |
|---|---|
| Mean | 65.9000 |
| Median | 66.0000 |
| Mode | 66.0000 |
| Sample Variance | 2.3222 |
| Sample Standard Deviation | 1.5239 |
| Population Variance | 2.0900 |
| Population Std. Deviation | 1.4457 |
| Range | 5.0000 |
| First Quartile (Q1) | 64.7500 |
| Third Quartile (Q3) | 67.0000 |
| Interquartile Range (IQR) | 2.2500 |
| Maximum | 69.0000 |
How does your height compare to the mean (average) height of the group that you surveyed?
My height is 5 feet 3 inches, which is 63 inches. This is shorter than the group’s average height of 65.9 inches.
How did you choose the participants for your study (sampling method)?
The data was gathered using convenience sampling. Due to restrictions during the COVID-19 pandemic, participants were chosen from a group of my friends and contacted via text message. While this method is convenient, it introduces sampling bias due to lack of randomization.
What part of the country did your study take place in?
The study was conducted in California, specifically in the Sacramento area.
What are the age ranges of your participants?
The participants in this sample were between the ages of 29 and 35 years.
How many of each gender did you have in your study?
The entire sample consisted of 10 female participants only.
What are other interesting factors about your group?
All participants are personal acquaintances, and most reside in California. The group is predominantly Caucasian, with 2 participants identifying as Hispanic. Interestingly, the two Hispanic women were the shortest among the group, though I was shorter than them all. Also, due to self-reported heights, some responses may be inaccurate, adding further bias to the sample.
Z-Score Calculation for a Given Height
To calculate the Z-score for a person who is 64 inches tall:
Formula:
Z = (x – mean) / standard deviation
Z = (64 – 65.9) / 1.5239 ≈ -1.2466
Empirical Rule Analysis
Using the Empirical Rule (68-95-99.7), we can determine the expected height ranges within each standard deviation from the mean.
| Coverage | Lower Bound | Upper Bound |
|---|---|---|
| 68% (±1σ) | 64.3761 | 67.4240 |
| 95% (±2σ) | 62.8522 | 68.9480 |
| 99.7% (±3σ) | 61.3283 | 70.4720 |
Interpretation:
- 68% of the heights fall between 64.4 and 67.4 inches
- 95% fall between 62.9 and 68.9 inches
- 99.7% fall between 61.3 and 70.5 inches
Given my height of 63 inches, this falls below the 68% and 95% range, indicating I am shorter than approximately 97.15% of the population in this sample.
MATH 225 Week 5 Assignment: Lab
Probability Calculations for Being Shorter or Taller Than 63 Inches
| Description | Value |
|---|---|
| Height (x) | 63 |
| Mean | 65.9 |
| Standard Deviation | 1.5239 |
| Z-score | -1.9030 |
| Probability < x | 0.0285 (2.85%) |
| Probability > x | 0.9715 (97.15%) |
Conclusion:
According to the normal distribution, only 2.85% of the sample is expected to be shorter than 63 inches. Therefore, I am in the lower tail of the height distribution.
References
Glen, S. (2020, September 20). Empirical Rule (68-95-99.7) & Empirical Research. Statistics How To. Retrieved October 2, 2020, from https://www.statisticshowto.com/empirical-rule-2/
MATH 225 Week 5 Assignment: Lab
Holmes, A., Illowsky, B., & Dean, S. (2019). Introductory business statistics (4.0). OpenStax. Retrieved from https://openstax.org/details/books/introductory-business-statistics