Math Problem Statement

How do I calculate the regression line for the given data points?

Solution

To calculate the regression line y=mx+by = mx + b, we need to compute the slope mm and the y-intercept bb using the following formulas:

m=n(xiyi)xiyinxi2(xi)2m = \frac{n \sum (x_i y_i) - \sum x_i \sum y_i}{n \sum x_i^2 - (\sum x_i)^2} b=yimxinb = \frac{\sum y_i - m \sum x_i}{n}

Where:

  • nn is the number of data points.
  • xix_i and yiy_i are the values of xx and yy, respectively.

Let me extract the data from the image and perform these calculations. numpy as np

Given data points from the image

x = np.array([2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]) y = np.array([19.4, 19.35, 16.9, 16.75, 19.4, 18.35, 21.5, 21.05, 18.5, 19.85, 21.2, 20.45])

Number of data points

n = len(x)

Calculating the slope (m)

m = (n * np.sum(x * y) - np.sum(x) * np.sum(y)) / (n * np.sum(x**2) - (np.sum(x)**2))

Calculating the y-intercept (b)

b = (np.sum(y) - m * np.sum(x)) / n

m, bThe regression line is:

y=0.23x+17.67y = 0.23x + 17.67

Would you like a detailed breakdown of the calculations or any further explanation?

Here are 5 related questions:

  1. How do we interpret the slope in this regression line?
  2. What does the y-intercept signify in this context?
  3. How can we calculate the correlation coefficient to measure the strength of this regression?
  4. Can the regression line predict temperatures for values of xx outside the given range?
  5. What assumptions are made when calculating a linear regression?

Tip: Always check the residuals (differences between observed and predicted values) to assess the fit of the regression line!

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Statistics
Algebra

Formulas

Slope formula: m = (n * Σ(x_i * y_i) - Σx_i * Σy_i) / (n * Σx_i^2 - (Σx_i)^2)
Y-intercept formula: b = (Σy_i - m * Σx_i) / n

Theorems

Least Squares Method

Suitable Grade Level

Grades 10-12