Finding the Fourth Proportional to 105,456.39, 145,529.82 and 57,709.74

Step by Step Solution

1. Step 1: Write the proportion equation
   105,456.39 : 145,529.82 = 57,709.74 : x
2. Step 2: Convert to fraction form
   105,456.39/145,529.82 = 57,709.74/x
3. Step 3: Cross multiply
   105,456.39x = 145,529.82 × 57,709.74
4. Step 4: Simplify right side
   105,456.39x = 8,398,488,074.45
5. Step 5: Solve for x
   x = 8,398,488,074.45/105,456.39
6. Step 6: Final answer
   x = 79,639.44