Math Problem Statement

The following table shows students’ test scores on the first two tests in an introductory calculus class.  

 Calculus Test ScoresFirst test, x

5353

9393

4545

6565

5757

6666

8686

6868

6666

4444

6565

5252

Second test, y

5757

9898

5353

6969

6565

7373

9292

8282

6464

5151

6767

4848

Copy Data 

Step 2 of 2 :  

If a student scored a 6161 on his first test, make a prediction for his score on the second test. Assume the regression equation is appropriate for prediction. Round your answer to two decimal places, if necessary.

Solution

To make a prediction for a student's score on the second test given a first test score of 61, we can use a linear regression model. The regression equation is generally of the form:

y=mx+by = mx + b

where:

  • yy is the predicted score on the second test,
  • xx is the first test score,
  • mm is the slope of the regression line,
  • bb is the y-intercept of the regression line.

Step 1: Calculate the Slope (mm) and Intercept (bb)

  1. Calculate the mean of xx (first test scores) and yy (second test scores).
  2. Calculate the slope (mm) using: m=(xxˉ)(yyˉ)(xxˉ)2m = \frac{\sum (x - \bar{x})(y - \bar{y})}{\sum (x - \bar{x})^2}
  3. Calculate the y-intercept (bb) using: b=yˉmxˉb = \bar{y} - m \bar{x}

Step 2: Substitute x=61x = 61 into the Regression Equation

Once we have mm and bb, we can substitute x=61x = 61 to predict the corresponding yy.

I'll calculate this now.The predicted score on the second test for a student who scored 61 on their first test is approximately 65.87.

Would you like further details on how the regression calculation was performed or any other questions?

Here are some related questions to explore:

  1. How is a regression line determined from a set of data points?
  2. What are some common uses of linear regression in real-world scenarios?
  3. How does the correlation between two variables affect the accuracy of predictions?
  4. What is the meaning of the slope and intercept in the context of this prediction?
  5. How would the prediction change if the student scored significantly higher or lower on the first test?

Tip: Linear regression is more reliable when there's a strong correlation between the variables involved.

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Math Problem Analysis

Mathematical Concepts

Statistics
Linear Regression
Predictive Modeling

Formulas

Linear regression equation: y = mx + b
Slope formula: m = (Σ(x - x̄)(y - ȳ)) / Σ(x - x̄)^2
Intercept formula: b = ȳ - m * x̄

Theorems

Least Squares Regression

Suitable Grade Level

Grades 10-12