To determine the number of centimeters in 1 inch, we can start with the given proportional relationship represented by the equation \( y = 15.24x \), where \( y \) is in centimeters and \( x \) is in inches.
In this context, when \( x = 1 \) inch:
\[ y = 15.24 \times 1 = 15.24 \text{ centimeters} \]
However, because the value of \( y \) for 6 inches is given to be 15.24 centimeters, we need to find the value of 1 inch based on the standard conversion factor.
The standard conversion from inches to centimeters is:
\[ 1 \text{ inch} = 2.54 \text{ centimeters} \]
So among the options:
- 0.39 centimeters
- 91.44 centimeters
- 2.54 centimeters
- 3 centimeters
The correct answer is 2.54 centimeters.