商务统计公式总结Word下载.doc

1、l Sample standard deviation l Coefficient of Variation l Z Score l Population mean l Population variance l Population standard deviation l Chebyshev Rule: at least （1 - 1/k2） x 100% of the values will fall within kl P（A or B） = P（A） + P（B） - P（A and B）ll Two events are independent if and only if: l

2、（If A and B are independent）l select X objects from n objects: （number of different ways）l select and arrange: l Expected Value （ mean） （discrete distribution） l Variance of a discrete random variable l Standard Deviation of a discrete random variable （X successes in n trials） Binomial Distribution

3、Mean Variance Standard Deviation Discrete ProbabilityDistributions （l=expected number of events; e = 2.71828.） Poisson Distribution Mean Standardized Normal Distribution translation of the Mean （is normal if population is normal or n 30） Sampling Distributionsof the Proportion（normal distribution if ） is Knownfor the Population Mean, Confidence Intervals is UnknownConfidence Intervals forthe Population Proportion, for meanDetermining Sample Size for proportion can be estimated with a pilot sample （or conservatively use = 0.5）