Finding the Fourth Proportional to 105,686.92, 145,857.15 and 57,949.57

Step by Step Solution

1. Step 1: Write the proportion equation
   105,686.92 : 145,857.15 = 57,949.57 : x
2. Step 2: Convert to fraction form
   105,686.92/145,857.15 = 57,949.57/x
3. Step 3: Cross multiply
   105,686.92x = 145,857.15 × 57,949.57
4. Step 4: Simplify right side
   105,686.92x = 8,452,359,123.93
5. Step 5: Solve for x
   x = 8,452,359,123.93/105,686.92
6. Step 6: Final answer
   x = 79,975.45