Final answer:
The weakest correlation coefficient among the provided options is d. +0.21 since it is closest to 0, indicating a weak relationship between the two variables. Option D is the correct answer.
Step-by-step explanation:
The concept in question is the correlation coefficient, which is a statistical measure used to indicate the strength and direction of the relationship between two variables. The correlation coefficient ranges from -1 to +1. A coefficient close to +1 or -1 indicates a strong relationship, whereas a coefficient close to 0 indicates a weak relationship.
Given the options:
- a. -1.00
- b. -0.43
- c. +0.66
- d. +0.21
Option d. +0.21 indicates the weakest relationship
This is because the absolute value 0.21 is closest to zero compared to the absolute values of the other options, signifying a weaker correlation.