stats chapter 6, section 1 & 2 Exam Questions and Answers

stats// chapter 6, section 1 & 2 Exam Questions and Answers random variable - Correct Answers: takes numerical values and their probabilities of a RANDOM VARIABLE probability distribution - Correct Answers: gives its possible values and their probabilities of a random variable mean (expected value) of a discrete random variable - Correct Answers: suppose that x is a discrete random variable with probability distribution multiply each possible value by its probability, then add all the products: Mx=E(x)= x1p1+x2p2+ x3p3+...= variance of a discrete random variable - Correct Answers: suppose that x is a discrete random variable with probability distribution and that the Mx is the mean of x, Var(x) = o^2x= (x1-mx)^2p1+ (x2-mx)^2p2+(x3-mx)^2p3+...= standard deviation of a discrete random variable - Correct Answers: suppose that x is a discrete random variable with probability disstribution and that Mx is the mean of x, ox= square root of variance continuous random variable - Correct Answers: x takes all values in an interval of numbers (the probability distribution of X is described by a density curve. the probability of any event is the area under the density curve and above the values of x that make up that event.) independent random variables - Correct Answers: if knowing whether any event involving x alone has occurred tells us nothing about the occurrence of any event involving y alone, and vice versa. linear transformation - Correct Answers: involves adding or subtracting constant a, multiplying or dividing by a constant b, or both mean of the sum of random variables - Correct Answers: for any two random variables x and y, if t= x+y, then e(t) = Mt=Mx=My variance of the sum of random variables - Correct Answers: for any two independent random variables x and y, if T=X+Y, then O^2t= O^2x+O^2y mean of the difference of random variables - Correct Answers: for any two random variables X and Y, if D= X-Y, then Md= E(D)= Mx-My variance of the difference of random variables - Correct Answers: for any two independent random variables X and Y, if D= X-Y, then O^2d= O^2x=+O^2y