Measuring dispersion

Measuring dispersion - or intervals between cases...

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Measuring dispersion : Ordinal Level Inter-quartile range : the range of values taken by the middle 50% of the cases inter-quartile because the endpoint are a quartile above a below the median value . 15-11= 4 We can see that the cases are very concentrated around the median. Measuring central tendency ( interval and ratio level) Central tendency : The measure of central tendency for interval/ ratio-level data is the mean or the average value. Simply sum the values and divide by the number of cases. The mean is the preferred measure of central tendency because it takes into account the distance
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Unformatted text preview: ( or intervals between cases) Inferential Statistic , Estimating Sampling Error Assume we have a sample and we want to find the sample values to make an inference about the population value Interpreting a normal distribution : We have to assume there are some sampling error Discrepancy the value we have taken for the sample and the true population value Using probability distribution : a theoretical distribution The highest point is the mean : The two halves have to match perfectly Median, mean and mode are the same...
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This note was uploaded on 02/06/2012 for the course POLI POLI-311-0 taught by Professor Melaneethomas during the Fall '10 term at McGill.

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