Math Problem Statement

Find the correlation coefficient and coefficient of determination (R²) from the given bivariate data set, and report them to three decimal places.

Solution

To solve this problem, we need to calculate the correlation coefficient rr and the coefficient of determination R2R^2 based on the bivariate data set. Here's how we can approach it:

The data set provided:

xy
24106.8
76.2-39.5
46.875.8
38.957.6
54.340.4

Step 1: Calculating the correlation coefficient rr

The correlation coefficient rr is calculated using the formula:

r=nxyxy(nx2(x)2)(ny2(y)2)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 data points.
  • xy\sum{xy} is the sum of the products of each pair xiyix_i y_i.
  • x\sum{x} and y\sum{y} are the sums of xx-values and yy-values respectively.
  • x2\sum{x^2} and y2\sum{y^2} are the sums of the squares of xx-values and yy-values.

Step 2: Coefficient of determination R2R^2

The coefficient of determination R2R^2 is simply the square of the correlation coefficient rr:

R2=r2R^2 = r^2

Now, let me calculate the values for you!The correlation coefficient rr is approximately 0.954-0.954, and the coefficient of determination R2R^2 is about 91.0%91.0\%. This means that about 91% of the variation in yy can be explained by the variation in xx.

Would you like further details on the calculations or have any questions?

Here are some related questions you might find interesting:

  1. What does a negative correlation coefficient indicate?
  2. How do you interpret the value of R2R^2?
  3. What are some factors that can affect the strength of a correlation?
  4. How do outliers impact the correlation coefficient?
  5. What is the difference between correlation and causation?

Tip: Always check if there are any outliers in your data, as they can significantly affect the correlation coefficient.

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Math Problem Analysis

Mathematical Concepts

Statistics
Correlation Coefficient
Coefficient of Determination

Formulas

Correlation coefficient formula: r = [n∑xy - (∑x)(∑y)] / sqrt[(n∑x² - (∑x)²)(n∑y² - (∑y)²)]
Coefficient of Determination: R² = r²

Theorems

Pearson's correlation coefficient

Suitable Grade Level

Grades 10-12 or introductory college-level statistics