31. Primary source data is (a) collected by someone else and then used by a statistician (b) collected and used by a statistician (c) another expression for a confidence interval (d) another expression for a parameter 32. Estimation gives a result that is almost always (a) an approximation (b) xact (c) primary source data (d) secondary source data 33. In order to get the best possible estimate of the standard deviation for a certain characteristic of an infinite population, we should (a) make the sample set as large as we can (b) use the smallest sample set we can get away with (c) test all the elements in the population (d) test 1000 elements at random 34. As the width of the confidence interval in a normal distribution decreases, the probability of a randomly selected element falling within that interval (a) decreases (b) does not change (c) increases (d) approaches a value of 68% 35. If items are repeatedly selected at random, with replacement, from a set of 750,000 elements: (a) the size of the set does not change (b) the size of the set increases (c) the size of the set decreases (d) the size of the set becomes zero