Finding the Fourth Proportional to 105,239, 145,239.81 and 57,499.54

Step by Step Solution

1. Step 1: Write the proportion equation
   105,239 : 145,239.81 = 57,499.54 : x
2. Step 2: Convert to fraction form
   105,239/145,239.81 = 57,499.54/x
3. Step 3: Cross multiply
   105,239x = 145,239.81 × 57,499.54
4. Step 4: Simplify right side
   105,239x = 8,351,222,264.69
5. Step 5: Solve for x
   x = 8,351,222,264.69/105,239
6. Step 6: Final answer
   x = 79,354.82