Math Problem Statement

Find the equation of the regression line based on the given data of age (x) and hours jogged per week (y), and determine if the correlation coefficient is significant at the 5% level.

Solution

Let's go through the problem step by step to determine the regression equation.

Given Data:

  • Age (xx) and Hours (yy) jogged per week:

    • x=[34,22,48,56,62]x = [34, 22, 48, 56, 62]
    • y=[3.5,7,2.5,2,1]y = [3.5, 7, 2.5, 2, 1]
  • Correlation coefficient, r=0.951r = -0.951, is also provided.

Step 1: Compute the Regression Line Equation

The equation of a linear regression line is given by: y=b0+b1xy = b_0 + b_1 x Where:

  • b1=rsysxb_1 = r \cdot \frac{s_y}{s_x} is the slope of the line.
  • b0=yˉb1xˉb_0 = \bar{y} - b_1 \cdot \bar{x} is the y-intercept.
  • xˉ\bar{x} and yˉ\bar{y} are the means of xx and yy.
  • sxs_x and sys_y are the standard deviations of xx and yy, respectively.

Step 2: Compute the necessary values

  • Means of xx and yy: xˉ\bar{x} and yˉ\bar{y}
  • Standard deviations of xx and yy: sxs_x and sys_y
  • Calculate slope b1b_1 and intercept b0b_0.

Let me calculate those values for you.The equation of the regression line is:

y=9.16530.1344xy = 9.1653 - 0.1344x

Both values are rounded to four decimal places as requested.

Interpretation:

  • The slope (b1=0.1344b_1 = -0.1344) indicates that for every additional year in age, the number of hours jogged per week decreases by approximately 0.1344 hours.
  • The intercept (b0=9.1653b_0 = 9.1653) represents the estimated number of hours jogged when the age is 0, which is more of a theoretical value for this context.

Would you like further details or explanations on any part of the calculation?


Here are 5 related questions you might explore:

  1. How would you interpret the correlation coefficient r=0.951r = -0.951?
  2. How do we determine if rr is significant at the 5% level?
  3. Can we use this regression equation for ages outside the provided data range?
  4. How would a positive correlation affect the slope of the line?
  5. What assumptions underlie the linear regression model?

Tip: Always check the residuals of your regression model to verify how well the model fits the data.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Statistics
Correlation

Formulas

y = b_0 + b_1 x
b_1 = r * (s_y / s_x)
b_0 = ȳ - b_1 * x̄

Theorems

Linear Regression Formula
Significance of Correlation Coefficient

Suitable Grade Level

Grades 10-12