Finding the Fourth Proportional to 21,831.30, 30,130.82 and 12,881.00

Step by Step Solution

1. Step 1: Write the proportion equation
   21,831.30 : 30,130.82 = 12,881.00 : x
2. Step 2: Convert to fraction form
   21,831.30/30,130.82 = 12,881.00/x
3. Step 3: Cross multiply
   21,831.30x = 30,130.82 × 12,881.00
4. Step 4: Simplify right side
   21,831.30x = 388,114,877.36
5. Step 5: Solve for x
   x = 388,114,877.36/21,831.30
6. Step 6: Final answer
   x = 17,777.91