Step 1 :We are given the following data pairs (x, y): (4, 2), (5, 9), (8, 10), (9, 12), (13, 23).
Step 2 :We are asked to find the correlation coefficient, or r-value, of this data to three decimal places.
Step 3 :The formula for the r-value is \(r = \frac{n(\sum xy) - (\sum x)(\sum y)}{\sqrt{[n\sum x^2 - (\sum x)^2][n\sum y^2 - (\sum y)^2]}}\), where n is the number of data pairs, \(\sum xy\) is the sum of the product of each pair of data, \(\sum x\) and \(\sum y\) are the sums of the x and y data respectively, and \(\sum x^2\) and \(\sum y^2\) are the sums of the squares of the x and y data respectively.
Step 4 :First, we calculate the necessary values for the formula: n = 5, \(\sum x\) = 39, \(\sum y\) = 56, \(\sum xy\) = 540, \(\sum x^2\) = 355, \(\sum y^2\) = 858.
Step 5 :Substituting these values into the formula, we find that r = 0.953.
Step 6 :Thus, the r-value of the given data, to three decimal places, is \(\boxed{0.953}\).