Math Problem Statement

A regression analysis from a sample of 15 15 produced the results shown below. Complete parts a through c. Use a 90 90​% confidence level where needed.

Summation from nothing to nothing left parenthesis x Subscript i Baseline minus x overbar right parenthesis left parenthesis y Subscript i Baseline minus y overbar right parenthesis ∑xi−xyi−y equals

153.6 153.6 Summation from nothing to nothing left parenthesis y Subscript i Baseline minus ModifyingAbove y with caret right parenthesis squared ∑yi−

y2 equals

39.532 39.532 Summation from nothing to nothing left parenthesis x Subscript i Baseline minus x overbar right parenthesis squared ∑xi−x2 equals

176.4 176.4 x overbar x equals

18.9 18.9 Summation from nothing to nothing left parenthesis y Subscript i Baseline minus y overbar right parenthesis squared ∑yi−y2 equals

182.6 182.6 y overbar y equals

50.5 50.5

Question content area bottom Part 1 a. Produce the regression line.

ModifyingAbove y with caret

y equals

34.0438 34.0438 plus +

0.8707 0.8707x ​(Round to four decimal places as​ needed.)

Part 2 b. Determine if there is a linear relationship between the dependent and independent variables. Use a significance level of 0.05 and a​ p-value approach.

Determine the null and alternative hypotheses. Choose the correct answer below.

A. H Subscript 0​: beta β Subscript 1 greater than or equals ≥0 H Subscript A​: beta β Subscript 1 less than <0

B. H Subscript 0​: beta β Subscript 1 equals =0 H Subscript A​: beta β Subscript 1 not equals ≠0 Your answer is correct.

C. H Subscript 0​: beta β Subscript 0 less than or equals ≤0 H Subscript A​: beta β Subscript 0 greater than

0

D. H Subscript 0​: beta β Subscript 0 equals =0 H Subscript A​: beta β Subscript 0 not equals ≠0

E. H Subscript 0​: beta β Subscript 0 greater than or equals ≥0 H Subscript A​: beta β Subscript 0 less than <0

F. H Subscript 0​: beta β Subscript 1 less than or equals ≤0 H Subscript A​: beta β Subscript 1 greater than

0

Part 3 Determine the test statistic.

t equals

enter your response here ​(Round to three decimal places as​ needed.)

Solution

Let's work through each part:

Part 1: Regression Line Equation

The regression line is given by: y^=34.0438+0.8707x\hat{y} = 34.0438 + 0.8707x This equation represents the line of best fit with an intercept of 34.0438 and a slope of 0.8707.

Part 2: Hypotheses and Significance Test

To determine if there is a linear relationship between the dependent (yy) and independent (xx) variables, we test if the slope β1\beta_1 is significantly different from zero.

Hypotheses:

Since we are looking for a relationship between xx and yy, the appropriate hypotheses would be:

  • Null hypothesis (H0H_0): β1=0\beta_1 = 0 (no linear relationship).
  • Alternative hypothesis (HAH_A): β10\beta_1 \neq 0 (there is a linear relationship).

So, the correct choice is: B. H0:β1=0andHA:β10H_0: \beta_1 = 0 \quad \text{and} \quad H_A: \beta_1 \neq 0

Part 3: Test Statistic

To calculate the test statistic tt for the slope β1\beta_1, we use the formula: t=β1^SE(β1^)t = \frac{\hat{\beta_1}}{SE(\hat{\beta_1})} where:

  • β1^=0.8707\hat{\beta_1} = 0.8707 (the estimated slope).
  • SE(β1^)=(yiy^)2(n2)(xixˉ)2SE(\hat{\beta_1}) = \sqrt{\frac{\sum (y_i - \hat{y})^2}{(n - 2) \cdot \sum (x_i - \bar{x})^2}}

Using the values given:

  • (yiy^)2=39.532\sum (y_i - \hat{y})^2 = 39.532
  • (xixˉ)2=176.4\sum (x_i - \bar{x})^2 = 176.4
  • n=15n = 15

Let's calculate SE(β1^)SE(\hat{\beta_1}) and then tt:

  1. Calculate SE(β1^)SE(\hat{\beta_1}): SE(β1^)=39.532(152)176.4SE(\hat{\beta_1}) = \sqrt{\frac{39.532}{(15 - 2) \cdot 176.4}}

  2. Substitute and solve: t=0.8707SE(β1^)t = \frac{0.8707}{SE(\hat{\beta_1})}

I'll calculate these values next.The test statistic tt for the slope β1\beta_1 is approximately 6.6326.632 (rounded to three decimal places).

Summary:

  • Regression Line: y^=34.0438+0.8707x\hat{y} = 34.0438 + 0.8707x
  • Hypotheses: H0:β1=0H_0: \beta_1 = 0, HA:β10H_A: \beta_1 \neq 0
  • Test Statistic tt: 6.6326.632

Would you like further details on any part of the process?


  1. What is the interpretation of the regression line?
  2. How can we interpret the tt-value obtained?
  3. What are the next steps if we were to perform the hypothesis test fully?
  4. How does the significance level influence our interpretation?
  5. What if we had a different confidence level—would it impact the conclusions?

Tip: When interpreting regression analysis results, always examine both the slope and tt-value to understand the strength and significance of relationships between variables.

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Math Problem Analysis

Mathematical Concepts

Regression Analysis
Hypothesis Testing
Linear Relationship
Confidence Interval

Formulas

Regression Line: ŷ = b₀ + b₁x
Test Statistic: t = (b₁) / SE(b₁)
Standard Error of Slope: SE(b₁) = sqrt(∑(yi - ŷ)^2 / [(n - 2) * ∑(xi - x̄)^2])

Theorems

Central Limit Theorem for Hypothesis Testing
Properties of Linear Regression

Suitable Grade Level

College Level - Introductory Statistics