Finding the Fourth Proportional to 126,128.72, 189,065.50 and 81,783.65

Step by Step Solution

1. Step 1: Write the proportion equation
   126,128.72 : 189,065.50 = 81,783.65 : x
2. Step 2: Convert to fraction form
   126,128.72/189,065.50 = 81,783.65/x
3. Step 3: Cross multiply
   126,128.72x = 189,065.50 × 81,783.65
4. Step 4: Simplify right side
   126,128.72x = 15,462,466,679.08
5. Step 5: Solve for x
   x = 15,462,466,679.08/126,128.72
6. Step 6: Final answer
   x = 122,592.75