RANDOM VARIABLES: probability distributions, means, …

STANDARD DEVIATION: This is just the square root of the variance and is used more often than variance. The notation is . Example to show that and variance and standard deviation are a measure of how data vary, that is, if the data is more variable these numbers are bigger. Consider the 3,3,5,6,13 example as well as 5,5,5,6,7,8. ................
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