MATH 225N Week 5 Discussion: The Normal Distribution
The Normal Distribution
MATH 225N
MATH225N
MATH 225N Week 5 Discussion: The Normal
... [Show More] Distribution
Initial Post Instructions
Many variables in medicine follow a normal distribution where there are approximately an equal number of values below the mean as above the mean. Describe two variables that you work with that would probably follow a normal distribution. Also note which of the two variables would be likely to have a larger standard deviation and why.
NB: 2 Answers Displayed
Answer 1
Statistical data is indispensable to physicians, and the knowledge of statistics is essential not only for research but also for understanding and interpreting information relevant to the practice of medical science (Holmes, Illowsky, & Dean, 2018; Sarkar, 2014). One of the elements of statistical data is normality, which is mainly characterized by a distribution that resembles a bell curve that is symmetrical. Half of the data will fall to the left of the mean; half will fall to the right. Two examples of variables that would have a normal distribution include systolic blood pressure and height. Systolic blood pressure readings are normally distributed, especially given that the mean and standard deviation are usually within the same range for a particular age group. For example, the systolic blood pressure of 18-year-old women is normally distributed, for instance, the mean is approximately 120 mmHg and standard deviation of 12 mmHg (Sarkar, 2014; Rivera et al., 2014). Height follows a normal distribution in the sense that most of the data values tend to cluster around the mean. However, systolic blood pressure would be likely to have a larger standard deviation because there are many factors that cause pressure to vary, such as health condition and lifestyle. Height remains fairly constant across age groups (Rivera et al., 2014).
References
Holmes, A., Illowsky, B. & Dean, S. (2018). Introductory business statistics. Houston, TX: OpenStax
Rivera, A. L., Estanol, B., Senties-Madrid, H., Fossion, R., Toledo-Roy, J. C., Mendoza-Temis, J., ... & Frank, A. (2016). Heart rate and systolic blood pressure variability in the time domain in patients with recent and long-standing diabetes mellitus. PloS one, 11(2), e0148378.
Sarkar, S. (2014). Understanding data for medical statistics. International Journal of Advanced Medical and Health Research, 1(1), 30.
Answer 2
As an alternative question, what are some other potential probability distributions in the health care field such as bimodal, skewed, or exponential and give variables that would probably follow that distribution.
Good afternoon professor:
Two variables that would probably follow a normal distribution in medicine are birth weight and prolactin (Campbell, 2007). With both variables we begin constructing a histogram with a determined size of sample as we studied in Chapter 2. After constructing the histogram we notice that both variables have the same shape characteristics: The mean is practically at the center of the histogram, the majority of the data is near to the mean and if we superimposed smooth ‘bell-shaped’ curve, we can see that the curve is symmetric. These are the characteristics of a Normal curve or Normal distribution. These two Normal distributions have the same shape and the difference between them are that each one has its own mean and its own standard deviation.
On the other hand, since standard deviation measures dispersion of the data; birth weight is more likely to have larger standard deviation than prolactin since the majority of people (male and female) have normal level of this hormone in comparison with the variety of birth weight in infants.
References
Campbell, Michael., Machin, David. (2007). Medical Statistics A Textbook for the Health Sciences, 69.
Holmes, A., Illowsky, B., & Dean, S. (2017). Introductory Business Statistics. Houston, TX: OpenStax CNX. Retrieved from https://openstax.org/details/books/introductory-business-statistics [Show Less]