Final answer:
The correlation coefficient, represented by the letter r, measures the degree of relationship between two variables, ranging from -1 to +1, with values close to the extremes indicating a strong relationship, and values near 0 indicating a weak relationship.
Step-by-step explanation:
The correlation coefficient is a statistical measure that describes the degree of relationship between two variables. It is commonly represented by the letter r and ranges from -1 to +1. When r is close to +1 or -1, it indicates a strong linear relationship between the variables, meaning they move together in a predictable pattern, either in the same direction (positive correlation) or in opposite directions (negative correlation). If r is around 0, it implies a weak or no linear relationship between the variables.
The formula to calculate the correlation coefficient r is complex but essentially assesses the covariance between two variables normalized by the product of their standard deviations. This calculation can reveal patterns in data that may not be immediately visible and is a powerful tool for data analysis, especially when considering the potential relationship between various factors.
Therefore, the correct answer to the student’s question is: d. the degree of relationship between two variables.