Math Problem Statement

For the data given​ below, answer parts ​(a) through ​(f). x negative 18 negative 15 negative 13 negative 12 negative 8 y 102 122 120 132 142

Solution

Let's begin by understanding the given dataLet's begin by understanding the given

  • x={18,15,13,12,8}x = \{-18, -15, -13, -12, -8\}
  • y={102,122,120,132,142}y = \{102, 122, 120, 132, 142\}

Now, let's address each part:

Part (a): Create a scatter plot of the data

To create a scatter plot, we plot each pair (x,y)(x, y) on a coordinate plane. Each xx-value is paired with a corresponding yy-value to form a point.

Part (b): Determine the correlation coefficient rr

The correlation coefficient rr measures the strength and direction of the linear relationship between xx and yy. It ranges from -1 (perfect negative correlation) to 1 (perfect positive correlation). We'll calculate this value.

Part (c): Describe the strength of the linear correlation

Using the correlation coefficient rr, we'll assess whether the relationship between xx and yy is strong, weak, or moderate.

Part (d): Find the equation of the regression line

We need to calculate the linear regression line, typically in the form: y=mx+by = mx + b where mm is the slope and bb is the y-intercept. This line best fits the given data points.

Part (e): Plot the regression line on the scatter plot

We'll plot the regression line on the same graph as the scatter plot to visualize how well it fits the data.

Part (f): Use the regression equation to predict the value of yy when x=10x = -10

Substitute x=10x = -10 into the regression equation found in part (d) to predict the corresponding yy-value.


I'll start by calculating the correlation coefficient rr, and the equation of the regression line. Let me compute these.### Part (b): The correlation coefficient rr is approximately 0.96. This indicates a very strong positive linear relationship between xx and yy.

Part (d): The equation of the regression line is:

y=3.86x+174.57y = 3.86x + 174.57

Now, I'll move on to predicting yy when x=10x = -10 (Part f).### Part (f): When x=10x = -10, the predicted value of yy is approximately 136.

Would you like to see the scatter plot with the regression line (Parts a and e), or need any further details?


Here are some related questions:

  1. How is the correlation coefficient interpreted in other cases (e.g., when rr is close to 0)?
  2. Can we apply linear regression to non-linear data? If not, why?
  3. What are the assumptions behind using a regression line?
  4. How would the prediction change if the slope was negative?
  5. What happens if we use more data points outside the current range of xx?

Tip: The closer the correlation coefficient rr is to 1 or -1, the stronger the linear relationship between the variables.

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Math Problem Analysis

Mathematical Concepts

Statistics
Linear Regression
Correlation

Formulas

Correlation coefficient formula: r = Σ((x - x̄)(y - ȳ)) / (√Σ(x - x̄)² * Σ(y - ȳ)²)
Linear regression equation: y = mx + b
Slope formula: m = Σ((x - x̄)(y - ȳ)) / Σ(x - x̄)²

Theorems

Least Squares Theorem

Suitable Grade Level

Grades 10-12