Statistical Sciences 2037A/B Lecture Notes - Lecture 15: Mammography
31 Oct 2018
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Expected value: the average value of any measurement over the long run (repeated independent trials) (or mean value) Identify all possible outcomes (a1, a2, a3, etc. Assign probabilities to each outcome (p1, p2, p3, etc. ) Can now calculate the expected value as the sum of each probability x the value of that outcome: ev= p1a1 + p2a2 + p3a3 + . E. g. a die rolling game that costs /play. the money won depends on what number rolls race-up on the fair die. Last column is the product of each probability and value of each outcome. Ev: sum the values and get -. 67 therefore not rational to play this game knowing the sum of values is negative. expected to lose . 67 per play. E. g. the probability of getting a parking ticket in london if you park on the street between 2 am and 5 am is 0. 10. The typical cost of this type of parking ticket is.
