Answer Happy

Suppose that we want to estimate the mean score on a nationwide examination in finance, and for this purpose we choose a random sample of exam scores. The sample we choose has a mean of 488 and a standard deviation of 80. For each of the following sampling scenarios, determine which test statistic is appropriate to use when making inference statements about the population mean. (In the table, Z refers to a variable having a standard normal distribution, and t refers to a variable having a t distribution.) Sampling Scenario Z t could use either Z or unclear t (1) The sample has size 75, and it is from a non- normally distributed population. O O O O о O O O o (2) The sample has size 11, and it is from a normally distributed population with unknown standard deviation. (3) The sample has size 19, and it is from a population with a distribution about which we know very little. (4) The sample has size 15, and it is from a normally distributed population with a known standard deviation of 75. (5) The sample has size 80, and it is from a non- normally distributed population with a known standard deviation of 75. o o O O O O o o х ?