Suppose that we want to estimate the mean PCB (Polychlorinated biphenyl) level in white croaker sh from the San Francisco Bay. The sample we select has a mean of 634 parts per million and a standard deviation of 50 parts per million. For each of the following sampling scenarios, determine which test statistic is appropriate to use when making inference statements about the mpulation mean. (In the table, Z refers to a variable having a standard normal distribution, and t refers to a variable having a t distribution.) could use Sampling Scenario 2 t either Z or unclear t (1) The sample has size 85, and it is from a non- O normally distributed population. (2) The sample has size 19, and it is from a normally distributed population with unknown standard deviation. (3) The sample has size 100, and it is from a non- normally distributed population with a known standard deviation of 52. (4) The sample has size 12, and it is from a population with a distribution about which we know very little. (5) The sample has size 14, and it is from a normally distributed population with a known standard deviation of 52