Finding the Fourth Proportional to 85,870.72, 128,741.28 and 56,296

Step by Step Solution

1. Step 1: Write the proportion equation
   85,870.72 : 128,741.28 = 56,296 : x
2. Step 2: Convert to fraction form
   85,870.72/128,741.28 = 56,296/x
3. Step 3: Cross multiply
   85,870.72x = 128,741.28 × 56,296
4. Step 4: Simplify right side
   85,870.72x = 7,247,619,098.88
5. Step 5: Solve for x
   x = 7,247,619,098.88/85,870.72
6. Step 6: Final answer
   x = 84,401.52