Stat 503 Exam 1 Solved 100% Correct

to show an association... {Ans: we need data that simultaneously compare the responses for at least two values of the explanatory variable}the greek letters {Ans: population mean denotes as Greek letter " μ'', population proportion denotes as "p" or population variance denotes as "σ2" etc. Statistics is a related quantity calculated from a sample. Sample mean denotes as "x ̅" , or sample proportion denotes as "p̂", or sample variance denotes as "s2".}constraints of stats {Ans: time and funding}To ensure a representative sample: {Ans: • Sample units must be selected randomly. • All units must have an equal chance of being included in the sample. • Each unit must be selected independently of all other units.}A distribution(or population distribution) {Ans: a mathematical function that describes the relative commonness or rarity of different values for a variable in a group - described by their shape, location, and spread}theoretical probability distributions {Ans: used to approximate the real probability distribution}