Finding the Fourth Proportional to 12,402.72, 17,105.76 and 7,678.08

Step by Step Solution

1. Step 1: Write the proportion equation
   12,402.72 : 17,105.76 = 7,678.08 : x
2. Step 2: Convert to fraction form
   12,402.72/17,105.76 = 7,678.08/x
3. Step 3: Cross multiply
   12,402.72x = 17,105.76 × 7,678.08
4. Step 4: Simplify right side
   12,402.72x = 131,339,393.74
5. Step 5: Solve for x
   x = 131,339,393.74/12,402.72
6. Step 6: Final answer
   x = 10,589.56