text 1 1. Suppose the population proportion is 0.38. What is the variance of the sample proportion, pp if the sample size is equal to 20? a) b) c) d) 0.10854 0.01178 4.712 0.2356 pp = p(1-p)/n =0.38(1-.38)/n = 0.01178 ANSWER IS B? 2. For any continuous random variable X, if both a and b are fixed real numbers such that a < b, then P(a X b) is always the same as: a) b) c) d) P(X a) P(X = a) + P(X = b) P( X b) - P(X a) P(X b) ANSWER IS C? 3. For any continuous random variable X, if a is some real constant, then P(X = a) is always: a) b) c) d) dependent upon the distribution of X. a positive nonzero value less than or equal to 1. equal to a. equal to zero. ANSWER IS D? 4. For any continuous random variable X, if a is some real constant, then P(X a) is always the same as: a) b) c) d) P(X < a) P(X a) P(X = a) 1 - P(X a) ANSWER IS D? 5. Suppose the random variable X is normally distributed with = 115 and = 10. What is P(100 X 115)? a) 0.5213 b) 0.6523 c) 0.4332 d) 0.5668 P(100 X 115) P(1.5 Z 0) 0.5 - 0.0668 =0.4332 ANSWER IS C