Variables Following a Normal Distribution
The various medical data captured in healthcare facilities are grouped into different variables. Among the variables, some follow a normal distribution while others follow other statistical distribution. The following variables follow a normal distribution: blood pressure, height, hemoglobin concentration, pregnancy length, height, and urinary lead concentration. This paper focuses on blood pressure and pregnancy length as the two variables that follow a normal distribution.
First, pregnancy length commonly follows a normal distribution. The average length of pregnancy is mostly calculated to be forty weeks. But in reality, the length may be shorter or longer than the forty weeks. Some women will deliver their newborns some days or some weeks before the forty days, while others will deliver a few days or weeks after the forty weeks. The variable follows a normal distribution, where some values are below the mean and a few are above the mean length. But the large proportion of values concentrates around the mean. The variance for pregnancy length is small since the difference between the lengths of pregnancies is small. Pregnancies cannot too long or too short time.
Secondly, the blood pressure of individuals exhibits properties of a normal distribution. Blood pressure is measured in mm HG and the normal pressure level is considered to be 120/80 mm Hg. But in some cases, the blood pressure can be below the normal or above the normal level. Most data about blood pressure concentrate around the normal which is considered as the mean. There are exceptional cases when the blood pressure of an individual is way above normal for those people with hypertension. When the population of patients is composed of many people suffering from hypertension and hypotension, the differences from the mean will be large. Thus, the variance of blood pressure will be slightly larger. The standard deviation of blood pressure will be larger than the standard deviation of pregnancy levels.