Finding the Fourth Proportional to 708,298.32, 977,339.88 and 398,139.72

Step by Step Solution

1. Step 1: Write the proportion equation
   708,298.32 : 977,339.88 = 398,139.72 : x
2. Step 2: Convert to fraction form
   708,298.32/977,339.88 = 398,139.72/x
3. Step 3: Cross multiply
   708,298.32x = 977,339.88 × 398,139.72
4. Step 4: Simplify right side
   708,298.32x = 389,117,826,168.03
5. Step 5: Solve for x
   x = 389,117,826,168.03/708,298.32
6. Step 6: Final answer
   x = 549,369.97