STAT 101 Lecture Notes - Lecture 10: Random Variable, Squared Deviations From The Mean, S&P 500 Index
Document Summary
Stat 101 - introduction to business statistics - lecture 10: random variables & A random variable is a variable whose value is not known with certainty. Operationally you can think of it as the uncertain outcome of an event that is yet to occur. Often we write the random variable as x and denote the probability that it takes on one of the specific values, x, as p(x = x). Note the upper and lower case x"s. The upper case x denotes the random variable and the lower case x, the value it takes. Ex) roll a six sided die once and let x be its outcome. P(x1 x x2) denotes the probability that x lies in the range [x1, x2]. For the die, p(1 x 4) = 2/3 because this event corresponds to 4 of the possible six outcomes and each is equally likely.
