Finding the Fourth Proportional to 199,851.72, 275,664.78 and 128,118.12

Step by Step Solution

1. Step 1: Write the proportion equation
   199,851.72 : 275,664.78 = 128,118.12 : x
2. Step 2: Convert to fraction form
   199,851.72/275,664.78 = 128,118.12/x
3. Step 3: Cross multiply
   199,851.72x = 275,664.78 × 128,118.12
4. Step 4: Simplify right side
   199,851.72x = 35,317,653,363.81
5. Step 5: Solve for x
   x = 35,317,653,363.81/199,851.72
6. Step 6: Final answer
   x = 176,719.29