Finding the Fourth Proportional to 139,929.72, 210,142.44 and 128,810.04

Step by Step Solution

1. Step 1: Write the proportion equation
   139,929.72 : 210,142.44 = 128,810.04 : x
2. Step 2: Convert to fraction form
   139,929.72/210,142.44 = 128,810.04/x
3. Step 3: Cross multiply
   139,929.72x = 210,142.44 × 128,810.04
4. Step 4: Simplify right side
   139,929.72x = 27,068,456,102.10
5. Step 5: Solve for x
   x = 27,068,456,102.10/139,929.72
6. Step 6: Final answer
   x = 193,443.22