Finding the Fourth Proportional to 103,405.56, 155,239.59 and 87,921.60

Step by Step Solution

1. Step 1: Write the proportion equation
   103,405.56 : 155,239.59 = 87,921.60 : x
2. Step 2: Convert to fraction form
   103,405.56/155,239.59 = 87,921.60/x
3. Step 3: Cross multiply
   103,405.56x = 155,239.59 × 87,921.60
4. Step 4: Simplify right side
   103,405.56x = 13,648,913,262.37
5. Step 5: Solve for x
   x = 13,648,913,262.37/103,405.56
6. Step 6: Final answer
   x = 131,994.00