ECON1310 Lecture Notes - Lecture 4: Random Variable, Weighted Arithmetic Mean, Standard Deviation
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Relative frequency: no. of times a particular event occurred, divided by the total number of all events that occurred. Outcomes must be: mutually exclusive outcomes, collectively exhaustive outcomes. Why are there lines and not bars: nothing between 25 and 50. Thicker lines do not show the exact values (might be 22 and not 25) Continuous probability distributions (for a random variable): continuous random variable = a variable that can take any value, at every point, over a given interval. Typically involves measuring/weighing e. g length of a fish: e. g normal distribution is a continuous probability distribution. The expected value/mean of a discrete random variable probability distribution. P(xi) = probability for the specific outcome for x being the weighting. *set up excel and complete example 1 (calculated e(x) = the average amount pledged) Variance (and standard deviation) of a discrete random variable probability distribution.
