Finding the Fourth Proportional to 105,456.57, 145,530.06 and 57,709.93

Step by Step Solution

1. Step 1: Write the proportion equation
   105,456.57 : 145,530.06 = 57,709.93 : x
2. Step 2: Convert to fraction form
   105,456.57/145,530.06 = 57,709.93/x
3. Step 3: Cross multiply
   105,456.57x = 145,530.06 × 57,709.93
4. Step 4: Simplify right side
   105,456.57x = 8,398,529,575.50
5. Step 5: Solve for x
   x = 8,398,529,575.50/105,456.57
6. Step 6: Final answer
   x = 79,639.70