Finding the Fourth Proportional to 100,659.81, 138,910.49 and 55,340.72

Step by Step Solution

1. Step 1: Write the proportion equation
   100,659.81 : 138,910.49 = 55,340.72 : x
2. Step 2: Convert to fraction form
   100,659.81/138,910.49 = 55,340.72/x
3. Step 3: Cross multiply
   100,659.81x = 138,910.49 × 55,340.72
4. Step 4: Simplify right side
   100,659.81x = 7,687,406,600.63
5. Step 5: Solve for x
   x = 7,687,406,600.63/100,659.81
6. Step 6: Final answer
   x = 76,370.17