Here are some properties of a normal distribution:
1. The normal curve is symmetrical about the mean μ
2. The mean is at the middle and divides the area into halves
3. The total area under the curve is equal to 1
4. It is completely determined by its mean and standard deviation σ (or variance σ2)
One can expect salary to be normally distributed. If the organization has employees of all age groups, even Age can also be a normal variate. Other variables such as education, gender, and ethnicity may not fit normal distribution due to be nonnumeric (Lind, Marchal, & Wathen, 2011).
Lind, D. A., Marchal, W. G., & Wathen, S. A. (2011). Basic statistics for business and economics (7th ed.). New York, NY: McGraw-Hill/Irwin.