Finding the Fourth Proportional to 280,945.50, 421,425.09 and 91,406.42

Step by Step Solution

1. Step 1: Write the proportion equation
   280,945.50 : 421,425.09 = 91,406.42 : x
2. Step 2: Convert to fraction form
   280,945.50/421,425.09 = 91,406.42/x
3. Step 3: Cross multiply
   280,945.50x = 421,425.09 × 91,406.42
4. Step 4: Simplify right side
   280,945.50x = 38,520,956,667.95
5. Step 5: Solve for x
   x = 38,520,956,667.95/280,945.50
6. Step 6: Final answer
   x = 137,111.85