Finding the Fourth Proportional to 85,404.60, 128,156.82 and 61,688.76

Step by Step Solution

1. Step 1: Write the proportion equation
   85,404.60 : 128,156.82 = 61,688.76 : x
2. Step 2: Convert to fraction form
   85,404.60/128,156.82 = 61,688.76/x
3. Step 3: Cross multiply
   85,404.60x = 128,156.82 × 61,688.76
4. Step 4: Simplify right side
   85,404.60x = 7,905,835,311.34
5. Step 5: Solve for x
   x = 7,905,835,311.34/85,404.60
6. Step 6: Final answer
   x = 92,569.20