Math Problem Statement

The table below shows the amount of time each of the 15 students in an introductory anthropology class spent studying for the first exam and the student's score on the exam out of 100. Predict the score for a student who studied for 1 hour 30 minutes and calculate how much time is needed to score at least 80.

Solution

Based on the provided image, we can extract the following information:

  1. The Problem Setup: The table shows the relationship between time spent studying (xx, in minutes) and exam scores (yy, out of 100). A linear regression equation y=mx+by = mx + b is needed to predict scores and study times.

  2. Equation: The regression equation provided in the image is: y=0.086x+71y = 0.086x + 71

Solving the Questions:

1. Predicting the Score:

For a student studying 1 hour 30 minutes (9090 minutes), substitute x=90x = 90 into the regression equation: y=0.086(90)+71y = 0.086(90) + 71 y=7.74+71=78.7479y = 7.74 + 71 = 78.74 \approx 79 The predicted score is 79 points.

2. Time Required to Score At Least 80:

Set y=80y = 80 and solve for xx: 80=0.086x+7180 = 0.086x + 71 8071=0.086x80 - 71 = 0.086x 9=0.086x9 = 0.086x x=90.086104.65x = \frac{9}{0.086} \approx 104.65 Rounded up, the time is approximately 105 minutes.

Let me know if you'd like a breakdown or further explanation for these calculations!


Further Learning:

Here are some related questions to deepen your understanding:

  1. What does the slope (m=0.086m = 0.086) represent in the context of this regression?
  2. How would the equation change if the intercept (b=71b = 71) were adjusted to account for a different baseline score?
  3. How does increasing study time impact scores based on the current slope?
  4. Could a quadratic model fit this data better? Why or why not?
  5. What are potential limitations of using this linear regression model for predicting scores?

Tip: Always verify your regression equation by calculating the residuals (differences between actual and predicted yy-values) to check the model's accuracy.

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Math Problem Analysis

Mathematical Concepts

Linear Regression
Algebra

Formulas

y = mx + b
x = (y - b) / m

Theorems

Slope-Intercept Form

Suitable Grade Level

Grades 9-12