Finding the Fourth Proportional to 105,085.96, 145,019.04 and 57,340.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,085.96 : 145,019.04 = 57,340.30 : x
2. Step 2: Convert to fraction form
   105,085.96/145,019.04 = 57,340.30/x
3. Step 3: Cross multiply
   105,085.96x = 145,019.04 × 57,340.30
4. Step 4: Simplify right side
   105,085.96x = 8,315,435,259.31
5. Step 5: Solve for x
   x = 8,315,435,259.31/105,085.96
6. Step 6: Final answer
   x = 79,129.84