Math Problem Statement

Based on the data shown below, use your graphing calculator or Excel to calculate the regression line (each value to two decimal places): x values: [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15], y values: [27.1, 27.9, 30.1, 34.6, 35.8, 40, 43.6, 46.7, 49.7, 49.1, 53.8, 56.5, 59, 60.7].

Solution

To find the regression line equation for the given data, we'll use the least-squares method to determine the slope (mm) and the y-intercept (bb) of the line in the form: y=mx+by = mx + b

Here is the data provided:

  • xx values: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
  • yy values: 27.1, 27.9, 30.1, 34.6, 35.8, 40, 43.6, 46.7, 49.7, 49.1, 53.8, 56.5, 59, 60.7

I'll compute the slope (mm) and intercept (bb) using the formulas: m=n(xy)xyn(x2)(x)2m = \frac{n \sum(xy) - \sum x \sum y}{n \sum(x^2) - (\sum x)^2} b=ymxnb = \frac{\sum y - m \sum x}{n}

Let me calculate these values.The regression line equation for the given data is: y=2.75x+20.56y = 2.75x + 20.56

This means the slope of the line is 2.752.75, and the y-intercept is 20.5620.56.

Would you like a detailed explanation of how these values were derived or have any further questions?

Here are five related questions that might expand your understanding:

  1. What does the slope of the regression line represent in this context?
  2. How can we interpret the y-intercept of this regression line?
  3. What is the coefficient of determination (R-squared) for this regression line?
  4. How do outliers affect the regression line calculation?
  5. What are some limitations of using linear regression for predictions?

Tip: The closer the slope and intercept are to real-world values, the more accurate your prediction is likely to be!

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Slope-Intercept Form
Statistics

Formulas

Slope (m) = [n Σ(xy) - Σx Σy] / [n Σ(x^2) - (Σx)^2]
Intercept (b) = [Σy - m Σx] / n

Theorems

Least Squares Method

Suitable Grade Level

Grades 10-12