Math Problem Statement

Based on the data shown below, calculate the regression line (show each value to two decimal places)

2

13.65

3

13.68

4

11.11

5

12.34

6

9.27

7

8

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x: 2,3,4,5,6,7

y: 13.65,13.68,11.11,12.34,9.27,8

 y=  x + 

Solution

To calculate the regression line, we need to find the equation of the line in the form:

y=mx+by = mx + b

Where:

  • mm is the slope of the line.
  • bb is the y-intercept.

Step 1: Find the slope (mm)

The formula for the slope is:

m=nxyxynx2(x)2m = \frac{n \sum{xy} - \sum{x} \sum{y}}{n \sum{x^2} - (\sum{x})^2}

Where:

  • nn is the number of data points (in this case, n=6n = 6).
  • xy\sum{xy} is the sum of the products of corresponding xx and yy values.
  • x\sum{x} is the sum of the xx values.
  • y\sum{y} is the sum of the yy values.
  • x2\sum{x^2} is the sum of the squares of the xx values.

Step 2: Find the y-intercept (bb)

The formula for the y-intercept is:

b=ymxnb = \frac{\sum{y} - m \sum{x}}{n}

Now, let's calculate the necessary values.

Given dataTo calculate the regression line, we need to find the equation of the line in the form:

y=mx+by = mx + b

Where:

  • mm is the slope of the line.
  • bb is the y-intercept.

Step 1: Find the slope (mm)

The formula for the slope is:

m=nxyxynx2(x)2m = \frac{n \sum{xy} - \sum{x} \sum{y}}{n \sum{x^2} - (\sum{x})^2}

Where:

  • nn is the number of data points (in this case, n=6n = 6).
  • xy\sum{xy} is the sum of the products of corresponding xx and yy values.
  • x\sum{x} is the sum of the xx values.
  • y\sum{y} is the sum of the yy values.
  • x2\sum{x^2} is the sum of the squares of the xx values.

Step 2: Find the y-intercept (bb)

The formula for the y-intercept is:

b=ymxnb = \frac{\sum{y} - m \sum{x}}{n}

Now, let's calculate the necessary values.

Given

x=[2,3,4,5,6,7]x = [2, 3, 4, 5, 6, 7] y=[13.65,13.68,11.11,12.34,9.27,8]y = [13.65, 13.68, 11.11, 12.34, 9.27, 8]

I'll now calculate these values step-by-step.The equation of the regression line is:

y=1.15x+16.52y = -1.15x + 16.52

Here:

  • The slope m=1.15m = -1.15
  • The y-intercept b=16.52b = 16.52

Would you like further details on any part of the calculation or have any other questions?

Here are 5 related questions to explore further:

  1. How would the regression line change if the data set included more points?
  2. What is the significance of the slope being negative in this case?
  3. How can we calculate the coefficient of determination (R2R^2) for this regression line?
  4. Can we predict the yy-value for an xx-value of 8 using this line?
  5. How does outlier data affect the regression line?

Tip: A negative slope means that as xx increases, yy decreases.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Statistics

Formulas

Slope formula: m = (nΣxy - ΣxΣy) / (nΣx^2 - (Σx)^2)
Y-intercept formula: b = (Σy - mΣx) / n
Linear regression equation: y = mx + b

Theorems

Least Squares Method

Suitable Grade Level

Grades 10-12