To find the number of centimeters in 1 inch from the relationship \( 6y = 15.24x \), we can set \( x = 1 \) inch and solve for \( y \).
Starting with the equation:
\[ 6y = 15.24x \]
Substituting \( x = 1 \):
\[ 6y = 15.24(1) \]
This simplifies to:
\[ 6y = 15.24 \]
Now, divide both sides by 6 to solve for \( y \):
\[ y = \frac{15.24}{6} = 2.54 \]
Thus, the number of centimeters in 1 inch is:
\[ \boxed{2.54} \text{ centimeters} \]