Use R

5. Working with two vectors. The sample correlation coefficient (r) is used to measure how strong a relationship is between two variables. Mathematically, the sample correlation coefficient of the data pairs (xi,yi),i=1,2,,n, is defined by: r=i=1n(xix)2i=1n(yiy)2i=1n(xix)(yiy) where x is the mean of xi 's and y is the mean of yi 's. Let's calculate the sample correlation coefficient between two variables, Sepal.Length and Sepal.width, in the data using the above formula. You can directly work with iris $S Sepal. Length and iris $ Sepal. width variables for the computation, but their names are too long. To make it simple, let's define new vectors x and y as follows: x