Biology 2244A/B Lecture Notes - Lecture 6: Confidence Interval, Point Estimation, Central Limit Theorem
2 Jan 2017
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2 parts of stats: descriptive stats and inferential stats; today we talk about inferential stats sampling error: distance between a statistic and a parameter: due to chance sample differences sampling distributions are theoretical only!! We would never actually do this: we will realistically only take one sample from a pop. , not many samples if we take srs of size two, the chart lists all the possible combinations of size two. X bar is the sample mean for each sample. We can then construct a frequency distribution for the values of sample mean: e. g. a sample mean of 2 only occurs once, sample mean of 3 occurs a total of 2 times. Sampling distribution: the probability distribution of a sample statistic, built from all possible samples of size n: for each sample size n, there are that many sampling distributions. This distribution is symmetrical, with a mean of 5: the sample mean is equivalent to the population mean.
