Math Problem Statement

Find the​ least-squares

regression

line treating number of absences as the explanatory variable and the final exam score as the response variable.

ModifyingAbove y with caretyequals=enter your response herexplus+enter your response here

​(Round to three decimal places as​ needed.) Number of absences, x Final exam score, y

0 90.2

1 87.2

2 82.9

3 80.7

4 77.9

5 73.9

6 64.5

7 71.6

8 65.4

9 65.7

Solution

To find the least-squares regression line (linear regression) of the form:

y^=mx+b\hat{y} = mx + b

where xx represents the number of absences (explanatory variable) and yy represents the final exam score (response variable), we need to calculate:

  1. The slope (mm).
  2. The intercept (bb).

Steps:

  1. Calculate the means of xx and yy.
  2. Find the slope mm using the formula:

m=(xixˉ)(yiyˉ)(xixˉ)2m = \frac{\sum{(x_i - \bar{x})(y_i - \bar{y})}}{\sum{(x_i - \bar{x})^2}}

  1. Find the intercept bb using the formula:

b=yˉmxˉb = \bar{y} - m\bar{x}

Let's compute that now.The least-squares regression line is:

y^=2.922x+89.151\hat{y} = -2.922x + 89.151

This equation predicts the final exam score (y^\hat{y}) based on the number of absences (xx).

Would you like further details or have any questions?

Here are some related questions to explore:

  1. How can you interpret the slope of the regression line?
  2. What is the predicted score for 5 absences?
  3. What would the model predict for 0 absences?
  4. How does the regression model perform with high numbers of absences?
  5. How can you test if this regression model fits the data well?

Tip: The slope of a regression line shows how much the response variable changes for each one-unit change in the explanatory variable.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Statistics
Least Squares Method

Formulas

Least-squares regression line: ŷ = mx + b
Slope: m = Σ((x_i - x̄)(y_i - ȳ)) / Σ((x_i - x̄)^2)
Intercept: b = ȳ - m * x̄

Theorems

Least-Squares Regression

Suitable Grade Level

Grades 10-12