Finding the Fourth Proportional to 101,111.80, 139,533.36 and 55,790.20

Step by Step Solution

1. Step 1: Write the proportion equation
   101,111.80 : 139,533.36 = 55,790.20 : x
2. Step 2: Convert to fraction form
   101,111.80/139,533.36 = 55,790.20/x
3. Step 3: Cross multiply
   101,111.80x = 139,533.36 × 55,790.20
4. Step 4: Simplify right side
   101,111.80x = 7,784,594,061.07
5. Step 5: Solve for x
   x = 7,784,594,061.07/101,111.80
6. Step 6: Final answer
   x = 76,989.97