Finding the Fourth Proportional to 156,978.24, 216,629.46 and 85,358.40

Step by Step Solution

1. Step 1: Write the proportion equation
   156,978.24 : 216,629.46 = 85,358.40 : x
2. Step 2: Convert to fraction form
   156,978.24/216,629.46 = 85,358.40/x
3. Step 3: Cross multiply
   156,978.24x = 216,629.46 × 85,358.40
4. Step 4: Simplify right side
   156,978.24x = 18,491,144,098.46
5. Step 5: Solve for x
   x = 18,491,144,098.46/156,978.24
6. Step 6: Final answer
   x = 117,794.31