Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these unlikely but serious side effects occur: vision changes (e.g., blurred vision), eye pain, easy bruising/bleeding, mental/mood changes, swelling of ankles /feet, unusual tiredness.
Standard Deviation and Variance. Deviation just means how far from the normal. Standard Deviation. The Standard Deviation is a measure of how spread out numbers are. Its symbol is Ï (the greek letter sigma) The formula is easy: it is the square root of the Variance.
The standard deviation is an especially useful measure of variability when the distribution is normal or approximately normal (see Chapter on Normal Distributions) because the proportion of the distribution within a given number of standard deviations from the mean can be calculated.