Math Problem Statement

Given the data shown below, which of the following is the best approximation of the coefficient of determination (R^2)? The data points are (1, 58), (2, 62), (3, 63), (4, 59), (5, 47), (6, 68), (7, 77), (8, 81), (9, 84), (10, 79), (11, 82), (12, 90).

Solution

To find the coefficient of determination (R2R^2), we need to first determine the linear regression equation that best fits the data and then calculate R2R^2, which measures the proportion of the variance in the dependent variable yy that can be explained by the independent variable xx.

The steps for solving this are as follows:

  1. Calculate the mean of xx and yy: xˉ=1+2++1212=6.5\bar{x} = \frac{1 + 2 + \ldots + 12}{12} = 6.5 yˉ=58+62++9012\bar{y} = \frac{58 + 62 + \ldots + 90}{12}

  2. Compute the slope mm of the regression line: m=(xixˉ)(yiyˉ)(xixˉ)2m = \frac{\sum{(x_i - \bar{x})(y_i - \bar{y})}}{\sum{(x_i - \bar{x})^2}}

  3. Find the intercept bb using: b=yˉmxˉb = \bar{y} - m\bar{x}

  4. Determine the predicted yy-values using the regression equation: y^=mx+b\hat{y} = mx + b

  5. Calculate R2R^2 using the formula: R2=1(yiy^)2(yiyˉ)2R^2 = 1 - \frac{\sum{(y_i - \hat{y})^2}}{\sum{(y_i - \bar{y})^2}}

By performing these calculations, the best approximation for the coefficient of determination will be identified. I’ll go through these calculations step-by-step now.The calculated coefficient of determination (R2R^2) is approximately 0.715. Since none of the provided answer choices exactly match this value, the closest approximation would be option B. 0.534.

Would you like more details on the calculations, or do you have any other questions?

Here are some related questions to expand your understanding:

  1. What is the significance of the slope and intercept in a linear regression equation?
  2. How does the coefficient of determination (R2R^2) relate to the correlation coefficient?
  3. What are some limitations of using linear regression for modeling relationships?
  4. How would you interpret an R2R^2 value close to 1 or close to 0?
  5. What is the impact of outliers on the R2R^2 value?

Tip: When interpreting R2R^2, remember that it represents the proportion of variance in the dependent variable that is predictable from the independent variable. The closer R2R^2 is to 1, the better the model explains the data.

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Math Problem Analysis

Mathematical Concepts

Statistics
Linear Regression
Coefficient of Determination

Formulas

R^2 = 1 - (Σ(y_i - ŷ_i)^2 / Σ(y_i - ȳ)^2)
ŷ = mx + b (linear regression equation)
m = Σ((x_i - ȳ)(y_i - ȳ)) / Σ(x_i - ȳ)^2 (slope calculation)

Theorems

Least Squares Method

Suitable Grade Level

Grades 10-12