In a normal distribution, what percentage of observations occur within one standard deviation of the mean?

In a normal distribution, approximately 68 percent of the observations fall within one standard deviation of the mean. This is a key characteristic of the normal distribution and is part of the empirical rule, also known as the 68-95-99.7 rule. The empirical rule helps to understand how data is spread around the mean; specifically, it indicates that about 68% of the data points will lie within one standard deviation in both directions (above and below the mean).

Knowing this concept is crucial for property appraisal, as it allows appraisers to assess how properties compare to the market average and understands the variability in property values when analyzing data distributions. This insight informs better decision-making regarding property valuations and market trends.