To determine the degrees of freedom for a contingency table representing the possibility of an association between blood type and eye color, we need to consider the number of rows and columns.
1. Identify the number of rows and columns in the table:
- In the given table, each group (A, B, C, D) represents a row. So, we have 4 rows.
- The eye colors (Blue, Green, Brown) represent the columns. So, we have 3 columns.
2. Calculate the degrees of freedom using the formula for a contingency table:
- The formula to calculate the degrees of freedom in a contingency table is [tex]\((\text{number of rows} - 1) \times (\text{number of columns} - 1)\)[/tex].
- Substitute the values: [tex]\((4 - 1) \times (3 - 1) = 3 \times 2\)[/tex].
3. Simplify the calculation:
- [tex]\(3 \times 2 = 6\)[/tex].
Therefore, the degrees of freedom for this contingency table are [tex]\(6\)[/tex].
Since the given question asks us to choose from the options:
a.) 7
We can clearly see that 7 is not the correct answer based on our calculations. The correct degrees of freedom is not listed in the provided option, but it is [tex]\(6\)[/tex].
