What do you get with mean minus std dev?

When you subtract the standard deviation from the mean, you get a value that represents one standard deviation below the average of a dataset. This can be useful for identifying lower thresholds in data analysis, such as determining the cutoff point for values that are considered below average. In a normal distribution, approximately 68% of the data falls within one standard deviation of the mean, so this value can help in understanding the spread of the data.