Finding the Fourth Proportional to 199,686.72, 275,099.34 and 139,147.50

Step by Step Solution

1. Step 1: Write the proportion equation
   199,686.72 : 275,099.34 = 139,147.50 : x
2. Step 2: Convert to fraction form
   199,686.72/275,099.34 = 139,147.50/x
3. Step 3: Cross multiply
   199,686.72x = 275,099.34 × 139,147.50
4. Step 4: Simplify right side
   199,686.72x = 38,279,384,037.15
5. Step 5: Solve for x
   x = 38,279,384,037.15/199,686.72
6. Step 6: Final answer
   x = 191,697.20