Finding the Fourth Proportional to 12,612.31, 17,405.38 and 7,578.77

Step by Step Solution

1. Step 1: Write the proportion equation
   12,612.31 : 17,405.38 = 7,578.77 : x
2. Step 2: Convert to fraction form
   12,612.31/17,405.38 = 7,578.77/x
3. Step 3: Cross multiply
   12,612.31x = 17,405.38 × 7,578.77
4. Step 4: Simplify right side
   12,612.31x = 131,911,294.23
5. Step 5: Solve for x
   x = 131,911,294.23/12,612.31
6. Step 6: Final answer
   x = 10,458.93