Stat 503 Exam 1 Solved 100% Correct

One major use of statistics is to... {Ans: relate one variable to another by examining associations between variables and differences between groups.}Volunteer bias (or response bias) {Ans: occurs with human subjects, when individuals who volunteer to participate in a study differ systematically from the general population}observational {Ans: - If values of the explanatory variable are not randomly assigned, the data... - can show association but cannot show cause-and-effect relationships.}estimation {Ans: the process of inferring an unknown quantity of a population using sample data - a.k.a. statistic - a related quantity calculated from a sample - approximation of the truth}If the sampling process favors some outcomes over others... {Ans: measurements made on the resulting samples might systematically underestimate (or overestimate) the population parameter}accuracy vs precision {Ans: Precision is about getting similar findings every time that we repeat a study, and accuracy is about correctly representing the real world, on average, over many replications of a study. They are not necessarily related, and it is completely possible to get results that are accurate by imprecise, or - much worse - precise, but biased.}