Math Problem Statement

can u explain this correlation step by step including the table

Find the correlation coefficient for the given data set for x and y.

Solution

Here's a step-by-step breakdown of the calculation of the correlation coefficient along with the data table:

Data Table:

xyxy
6244384419362728
6043360018492580
6044360019362640
5939348115212301
5838336414442204
5638313614442128
5535302512251925

Steps to Calculate Correlation Coefficient:

  1. Sum the variables:

    • Sum of xx: x=410\sum x = 410
    • Sum of yy: y=281\sum y = 281
    • Sum of x2x^2: x2=24050\sum x^2 = 24050
    • Sum of y2y^2: y2=11355\sum y^2 = 11355
    • Sum of xyxy: xy=16506\sum xy = 16506
  2. Apply the Pearson Correlation formula: [ r = \frac{n \cdot \sum (xy) - \sum x \cdot \sum y}{\sqrt{[n \cdot \sum x^2 - (\sum x)^2] \cdot [n \cdot \sum y^2 - (\sum y)^2]}} ] Where:

    • n=7n = 7 (number of data points)

    Substituting the values into the formula:

    Numerator: 716506410281=115542115210=3327 \cdot 16506 - 410 \cdot 281 = 115542 - 115210 = 332

    Denominator: [ \sqrt{[7 \cdot 24050 - 410^2] \cdot [7 \cdot 11355 - 281^2]} = \sqrt{(168350 - 168100) \cdot (79485 - 78961)} = \sqrt{250 \cdot 524} \approx 362.09 ]

    Finally: r=332362.090.917r = \frac{332}{362.09} \approx 0.917

Correlation Coefficient:

r0.917r \approx 0.917

This indicates a strong positive correlation between the variables xx and yy.

Do you want more details on any step or have any questions?

Additional Questions:

  1. How is the regression equation derived from this data?
  2. What does a correlation coefficient of 0.917 signify in practical terms?
  3. How does one test the significance of this correlation coefficient?
  4. What if there were more points added to the dataset—how would this impact the correlation?
  5. Can the correlation be negative, and what would that imply for this type of data?

Tip:

When calculating the correlation coefficient, always ensure that both variables have a linear relationship, as the Pearson method assumes linearity between variables.

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Math Problem Analysis

Mathematical Concepts

Statistics
Correlation
Regression Analysis

Formulas

Pearson Correlation Coefficient Formula: r = (nΣxy - ΣxΣy) / sqrt((nΣx² - (Σx)²)(nΣy² - (Σy)²))

Theorems

Pearson's Correlation Coefficient

Suitable Grade Level

College-level Statistics or Grades 11-12