Biology 2244A/B Lecture Notes - Lecture 8: Normal Distribution, Standard Deviation, Unimodality
12 Jun 2016
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The probability a normal rv takes a value within. 1 sd of its mean is about 0. 68. 2 sds of its mean is about 0. 95. 3 sds of its mean is about 0. 997. Normal distribution n(0, 1) with mean 0 and standard deviation 1. Have to have sigma bigger than 0. Solve using z tables and properties of normal and/or densities. Translate back to original normal distribution if necessary. 99. 7% of the observations are expected to be within 3 sds of the mean: q-q plot (pp plot) Don"t want any clear, nonlinear patterns in points around the line. Take random sample from pop and calc appropriate statistic (an estimate of parameter) Sample is subset of pop so the statistic and parameter will likely not be equal; the statistic will vary from sample to sample (sampling variability [same as sampling error])
