Finding the Fourth Proportional to 12,864.48, 17,756.32 and 7,278.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,864.48 : 17,756.32 = 7,278.72 : x
2. Step 2: Convert to fraction form
   12,864.48/17,756.32 = 7,278.72/x
3. Step 3: Cross multiply
   12,864.48x = 17,756.32 × 7,278.72
4. Step 4: Simplify right side
   12,864.48x = 129,243,281.51
5. Step 5: Solve for x
   x = 129,243,281.51/12,864.48
6. Step 6: Final answer
   x = 10,046.52