Finding the Fourth Proportional to 105,087.84, 145,019.28 and 57,339.96

Step by Step Solution

1. Step 1: Write the proportion equation
   105,087.84 : 145,019.28 = 57,339.96 : x
2. Step 2: Convert to fraction form
   105,087.84/145,019.28 = 57,339.96/x
3. Step 3: Cross multiply
   105,087.84x = 145,019.28 × 57,339.96
4. Step 4: Simplify right side
   105,087.84x = 8,315,399,714.43
5. Step 5: Solve for x
   x = 8,315,399,714.43/105,087.84
6. Step 6: Final answer
   x = 79,128.09