Biology 2244A/B Lecture Notes - Lecture 18: Multivariate Normal Distribution, Centroid, Scatter Plot
11 Dec 2013
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Document Summary
Basic concepts: correlation relationship between 2 variables, use a scatter plot. X and y represent a one of the two variables used and are plotted together: linear correlation coefficient (r) sample statistic. Measures strength of correlation in a sample. Also, pairs of data must have bivariate normal distribution. For and x, y must be bell shaped and vice versa. If value from table less than computed r value, significant linear correlation. Write as since r=?, its absolute value does exceed ? so we conclude that there is a significant linear correlation between x and y. Value of r doesn"t change if all values for 1 variable converted to different scale. Value of r not affected by choice of x or y r measures strength of linear association interpreting r. Value of r^2 is proportion of variation in y explained by linear association between x and y.
