answer questions please explain briefly

Suppose that you are working for a team that is developing a new vaccine. The vaccine is in the advanced stages of a clinical trial, in which you are monitoring the effectiveness of the vaccine in a sample of people. Your elderly cousin, who is not participating in the trial, is excited about the possibility of getting vaccinated, so that she can go to the grocery store more often. She asks you "So, how effective is the vaccine?" What is she asking about? 0 The sample 0 The population Suppose that a box contains 100 tickets, of which some unknown number M are 1's. If you randomly sample 36 different tickets out of the box, what is the standard error of your resulting estimate of the proportion of tickets in the box that are 1's? ()1 0100 00 0 Not enough information given All other things equal, estimation in case of relatively heterogeneous populations will tend to be more difficult O True O FalseYou will estimate the proportion of feral cats in a population that have been fixed, using an independent sample. For which (hypothetical) proportion of fixed cats would you have the best estimate? O 0.50 O 0.08 O 0.52 O 0.09 O 0.31Suppose that a researcher is going to estimate an unknown proportion from a binary population on the basis of a sample that she will obtain from this population. Suppose that the population has size N=201. If sampling without replacement here would give an estimator that is twice as accurate (as measured by the SE) as the estimator obtained by sampling with replacement, what is the sample size