Finding the Fourth Proportional to 105,139.23, 145,089.86 and 57,393.38

Step by Step Solution

1. Step 1: Write the proportion equation
   105,139.23 : 145,089.86 = 57,393.38 : x
2. Step 2: Convert to fraction form
   105,139.23/145,089.86 = 57,393.38/x
3. Step 3: Cross multiply
   105,139.23x = 145,089.86 × 57,393.38
4. Step 4: Simplify right side
   105,139.23x = 8,327,196,456.71
5. Step 5: Solve for x
   x = 8,327,196,456.71/105,139.23
6. Step 6: Final answer
   x = 79,201.61