Short questions

QUESTION 1 If A is any event ofa sample space S and if PtA) is computed using P(A) : n(A) 311(3) then ntA} may never equal zero. QUESTION 2 If either event A or event B must occur, then A and B are mutually exclusive and collectively exhaustive events. QUESTION 3 Odds are a way of expressing probabilities by expressing the number of ways an event can happen compared to the number of ways it can't happen. QUESTION 4 The mean of a discrete probability distribution for X is the sum of all possible values of X, divided by the number of possible values of X. QUESTION 5 Faculty rank (professor, associate professor, assistant professor, and lecturer) is an example of a discrete random variable. QUESTION 5 For a random variable X , if V (cX} = 4V (XL where It refers to the variance. then c must be 4. QUESTION 7 The average ntunber of customers arriving at a department store in a 5minute period has a Pois son distribution. QUESTION 8 The binomial random variable X is the count of the number of successful trials that occur in 11 trials. The random variable X may take on any real value from zero to n. QUESTION 9 A continuous random variable X has a uniform distribution between 5 and 15 {inclusive}, then the probability that X falls between II} and 20 is 1.0. QUESTION 10 In practice, we frequently use a continuous distribution to approximate a discrete one when the ntunber of values the variable can assume is countable but large