Math Problem Statement

The following data gives the number of hours 10 students spent studying and their corresponding grades on their midterm exams.

Hours Spent Studying 0.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Midterm Grades 63 66 69 72 75 81 84 90 96 99 Calculate the correlation coefficient, r. Round your answer to three decimal places.

Solution

To calculate the correlation coefficient rr, we can use the formula:

[ r = \frac{n(\sum xy) - (\sum x)(\sum y)}{\sqrt{[n \sum x^2 - (\sum x)^2][n \sum y^2 - (\sum y)^2]}} ]

Where:

  • nn is the number of data points (in this case, 10),
  • xx represents the hours spent studying,
  • yy represents the midterm grades,
  • x\sum x is the sum of all the xx-values,
  • y\sum y is the sum of all the yy-values,
  • xy\sum xy is the sum of the product of corresponding xx and yy-values,
  • x2\sum x^2 is the sum of the squares of the xx-values,
  • y2\sum y^2 is the sum of the squares of the yy-values.

Step-by-Step Calculation:

Let me compute it now.It seems like I can’t do more advanced data analysis right now. Please try again later. If you'd like, I can walk you through the manual steps for calculating the correlation coefficient, or you can upload the data again later for a direct calculation.

Would you like details on the manual calculation? Here are some related questions that could extend your understanding:

  1. How does the correlation coefficient rr help in determining the strength of a relationship?
  2. What does a positive or negative rr value indicate about two variables?
  3. Can the correlation coefficient ever exceed 1 or be less than -1?
  4. What is the difference between correlation and causation?
  5. How can we graph the relationship between hours studied and midterm grades?

Tip: When calculating rr, it's important to ensure that the data is well-formed and the relationship is linear for the coefficient to be meaningful.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Statistics
Correlation
Linear Relationships

Formulas

Correlation coefficient formula r = [n(Σxy) - (Σx)(Σy)] / √[nΣx² - (Σx)²][nΣy² - (Σy)²]

Theorems

Pearson correlation coefficient

Suitable Grade Level

Grades 9-12