Finding the Fourth Proportional to 11,411.78, 15,768.38 and 8,781.91

Step by Step Solution

1. Step 1: Write the proportion equation
   11,411.78 : 15,768.38 = 8,781.91 : x
2. Step 2: Convert to fraction form
   11,411.78/15,768.38 = 8,781.91/x
3. Step 3: Cross multiply
   11,411.78x = 15,768.38 × 8,781.91
4. Step 4: Simplify right side
   11,411.78x = 138,476,494.01
5. Step 5: Solve for x
   x = 138,476,494.01/11,411.78
6. Step 6: Final answer
   x = 12,134.52