Math Problem Statement

The following table gives the data for the average temperature and the snow accumulation in several small towns for a single month. Determine the equation of the regression line, yˆ=b0+b1x. Round the slope and y-intercept to the nearest thousandth. Then determine if the regression equation is appropriate for making predictions at the 0.05 level of significance.

Critical Values of the Pearson Correlation Coefficient

Average Temperatures and Snow Accumulations Average Temperature (℉) 39 29 20 44 45 15 34 25 28 42 Snow Accumulation (in.) 7 19 22 10 14 29 22 19 20 5

Solution

To determine the equation of the regression line, we first need to calculate the slope (b1b_1) and the intercept (b0b_0) of the line, as well as test if the regression equation is statistically significant at the 0.050.05 level of significance.

Step 1: Organize Data

Let xx be the Average Temperature (℉) and yy be the Snow Accumulation (in.).

  • x=[39,29,20,44,45,15,34,25,28,42]x = [39, 29, 20, 44, 45, 15, 34, 25, 28, 42]
  • y=[7,19,22,10,14,29,22,19,20,5]y = [7, 19, 22, 10, 14, 29, 22, 19, 20, 5]

Step 2: Calculate the Slope and Intercept

The formula for the slope (b1b_1) is:

b1=nxyxynx2(x)2b_1 = \frac{n \sum xy - \sum x \sum y}{n \sum x^2 - (\sum x)^2}

The formula for the intercept (b0b_0) is:

b0=yˉb1xˉb_0 = \bar{y} - b_1 \bar{x}

Where:

  • nn is the number of data points (here, n=10n = 10),
  • xy\sum xy is the sum of the products of xx and yy,
  • x\sum x and y\sum y are the sums of xx and yy respectively,
  • x2\sum x^2 is the sum of the squares of xx,
  • xˉ\bar{x} and yˉ\bar{y} are the means of xx and yy.

Let's calculate these values.The equation of the regression line is:

y^=36.4540.615x\hat{y} = 36.454 - 0.615x

Now, we need to determine if the regression equation is appropriate for making predictions at the 0.050.05 level of significance by testing the significance of the slope using the Pearson correlation coefficient (rr).

Step 3: Calculate the Pearson Correlation Coefficient (rr)

The formula for rr is:

r=nxyxy(nx2(x)2)(ny2(y)2)r = \frac{n \sum xy - \sum x \sum y}{\sqrt{(n \sum x^2 - (\sum x)^2)(n \sum y^2 - (\sum y)^2)}}

We will also need to check the critical values of rr from a table (depending on n2=8n-2 = 8 degrees of freedom). Let's calculate the correlation coefficient rr.It seems like I can’t do more advanced data analysis right now. Please try again later.

Would you like help with the Pearson correlation coefficient calculation manually, or any further clarification about the regression process?

Here are 5 follow-up questions you might find interesting:

  1. How is the Pearson correlation coefficient interpreted?
  2. What does it mean if the slope of the regression line is close to zero?
  3. How can we test the hypothesis for the significance of the slope in a regression?
  4. What is the difference between simple linear regression and multiple linear regression?
  5. How do we interpret the R-squared value in a regression analysis?

Tip: Always check the assumptions of linear regression before making predictions, such as the linearity of the relationship and homoscedasticity of residuals.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Pearson Correlation Coefficient
Statistical Significance Testing

Formulas

Regression Line: yˆ = b0 + b1x
Slope (b1): b1 = (nΣxy - ΣxΣy) / (nΣx^2 - (Σx)^2)
Intercept (b0): b0 = ȳ - b1x̄
Pearson Correlation Coefficient: r = (nΣxy - ΣxΣy) / √[(nΣx^2 - (Σx)^2)(nΣy^2 - (Σy)^2)]

Theorems

Linear Regression Theorem
Pearson Correlation Coefficient Significance Test

Suitable Grade Level

Grades 10-12