Finding the Fourth Proportional to 131,407.20, 196,824.50 and 86,377.72

Step by Step Solution

1. Step 1: Write the proportion equation
   131,407.20 : 196,824.50 = 86,377.72 : x
2. Step 2: Convert to fraction form
   131,407.20/196,824.50 = 86,377.72/x
3. Step 3: Cross multiply
   131,407.20x = 196,824.50 × 86,377.72
4. Step 4: Simplify right side
   131,407.20x = 17,001,251,118.25
5. Step 5: Solve for x
   x = 17,001,251,118.25/131,407.20
6. Step 6: Final answer
   x = 129,378.39