Finding the Fourth Proportional to 21,111.54, 31,671.83 and 7,784.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111.54 : 31,671.83 = 7,784.57 : x
2. Step 2: Convert to fraction form
   21,111.54/31,671.83 = 7,784.57/x
3. Step 3: Cross multiply
   21,111.54x = 31,671.83 × 7,784.57
4. Step 4: Simplify right side
   21,111.54x = 246,551,632.52
5. Step 5: Solve for x
   x = 246,551,632.52/21,111.54
6. Step 6: Final answer
   x = 11,678.52