Math Problem Statement

Here is a bivariate data set.

xy

83

24

68

26

67

27

71

3

68

17

71

23

74

32

79

38

Find the correlation coefficient and report it accurate to four decimal places.  r =

Solution

To calculate the correlation coefficient rr, we can use the formula:

[ 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:

  • nn is the number of pairs
  • x\sum x is the sum of all xx values
  • y\sum y is the sum of all yy values
  • xy\sum xy is the sum of the products of corresponding xx and yy values
  • x2\sum x^2 is the sum of the squares of all xx values
  • y2\sum y^2 is the sum of the squares of all yy values

First, let's organize the dataTo calculate the correlation coefficient rr, we can use the formula:

[ 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:

  • nn is the number of pairs
  • x\sum x is the sum of all xx values
  • y\sum y is the sum of all yy values
  • xy\sum xy is the sum of the products of corresponding xx and yy values
  • x2\sum x^2 is the sum of the squares of all xx values
  • y2\sum y^2 is the sum of the squares of all yy values

First, let's organize the

x=[8,6,7,1,6,7,4,9]x = [8, 6, 7, 1, 6, 7, 4, 9] y=[3,8,7,3,7,1,2,8]y = [3, 8, 7, 3, 7, 1, 2, 8]

Now I'll calculate the necessary sums and plug them into the formula.The correlation coefficient rr is approximately 0.37330.3733, accurate to four decimal places.

Would you like more details or have any questions?

Here are 5 related questions to expand on this:

  1. How is the correlation coefficient interpreted in terms of strength and direction?
  2. What does a correlation coefficient of 0.3733 imply about the relationship between the variables?
  3. How would the correlation coefficient change if an outlier were introduced?
  4. What other methods are available to determine the strength of a relationship between two variables?
  5. Can correlation coefficients be used for non-linear relationships?

Tip: Always visualize your data with a scatter plot to better understand the relationship between variables before relying on the correlation coefficient alone.

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Math Problem Analysis

Mathematical Concepts

Statistics
Correlation Coefficient
Bivariate Data Analysis

Formulas

r = (n(∑xy) - (∑x)(∑y)) / sqrt([n∑x^2 - (∑x)^2][n∑y^2 - (∑y)^2])

Theorems

Pearson Correlation Coefficient

Suitable Grade Level

Grades 11-12