Finding the Fourth Proportional to 100,420.56, 138,581.76 and 55,097.72

Step by Step Solution

1. Step 1: Write the proportion equation
   100,420.56 : 138,581.76 = 55,097.72 : x
2. Step 2: Convert to fraction form
   100,420.56/138,581.76 = 55,097.72/x
3. Step 3: Cross multiply
   100,420.56x = 138,581.76 × 55,097.72
4. Step 4: Simplify right side
   100,420.56x = 7,635,539,009.59
5. Step 5: Solve for x
   x = 7,635,539,009.59/100,420.56
6. Step 6: Final answer
   x = 76,035.61