Questions and CORRECT Answers
estimation process - CORRECT ANSWER - the process to estimate a target parameter of
population
target parameter - CORRECT ANSWER - the unknown population parameter
point estimator - CORRECT ANSWER - a rule or formula that tells us how to use the
sample data to calculate a single value that can be used as an estimate of the target parameter
confidence interval - CORRECT ANSWER - a rule or formula that tells us how to use
sample data to calculate an interval that estimates the target parameter. contains a confidence
level, a percentage, also known as a reliability coefficient
conditions required for valid large-sample confidence interval - CORRECT ANSWER - 1.
random sample selected from target population
2. sample size is > 30
-Due to Central Limit Theorem, this condition guarantees that the sampling distribution of X will
be approximately normal. Also, large n means that s will be a good estimator for sigma.
how to narrow a confidence interval - CORRECT ANSWER - 1. increase the sample size
2. decrease the confidence level
Central Limit Theorem - CORRECT ANSWER - If you have a large sample ( n > 30 ),
normal distribution will occur.
William Gosset - CORRECT ANSWER - invented student's t-distribution
similarities of z-statistic and t-statistic distribution - CORRECT ANSWER - -symmetric