| a quantity formerly used as a measure of variability: equal to 0.6745 times the standard deviation. A normally distributed population has half of its elements within one probable error of the mean. |
| probable error n. Abbr. PE The amount by which the arithmetic mean of a sample is expected to vary because of chance alone. |
probable error  (prŏb'ə-bəl) Pronunciation Key
The amount by which the arithmetic mean of a sample is expected to vary because of chance alone. |