Math Problem Statement

Suppose a doctor measures the​ height, x, and head​ circumference, y, of 8 children and obtains the data below. The correlation coefficient is

0.9690.969

and the least squares regression line is

ModifyingAbove y with caret equals 0.200 x plus 11.950y=0.200x+11.950.

Complete parts ​(a) and​ (b)**** below.

​Height, x

27.2527.25

25.2525.25

26.2526.25

25.2525.25

27.527.5

26.7526.75

25.7525.75

26.7526.75

2727

26.7526.75

26.7526.75   Head​ Circumference, y

17.317.3

17.017.0

17.217.2

17.017.0

17.517.5

17.317.3

17.117.1

17.317.3

17.417.4

17.317.3

17.317.3

Question content area bottom

Part 1

​(a)**** Compute the coefficient of​ determination,

Upper R squaredR2.

Upper R squaredR2equals=enter your response here​%

​(Round to one decimal place as​ needed.)

Solution

The coefficient of determination, R2R^2, is calculated as the square of the correlation coefficient, rr.

Given: r=0.969r = 0.969

To compute R2R^2: R2=r2=(0.969)2=0.9391R^2 = r^2 = (0.969)^2 = 0.9391

Convert to percentage: R2=0.9391×100=93.9%R^2 = 0.9391 \times 100 = 93.9\%

Final Answer:

The coefficient of determination, R2R^2, is 93.9%.


Would you like to proceed to part (b) or need further clarification?

Here are 5 related questions to deepen your understanding:

  1. What does the coefficient of determination tell us about the data?
  2. How is the correlation coefficient interpreted in the context of a regression model?
  3. How can outliers affect the correlation and determination coefficients?
  4. What are the assumptions behind least-squares regression?
  5. How does R2R^2 differ from adjusted R2R^2?

Tip: A high R2R^2 value indicates a strong linear relationship, but always check residual plots to confirm the model's validity!

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Math Problem Analysis

Mathematical Concepts

Correlation
Regression Analysis
Coefficient of Determination

Formulas

Coefficient of determination: R² = r²
Linear regression equation: y = mx + b

Theorems

Least Squares Method
Properties of Correlation Coefficient

Suitable Grade Level

Grades 10-12