Finding the Fourth Proportional to 105,139.71, 145,092.38 and 57,393.09

Step by Step Solution

1. Step 1: Write the proportion equation
   105,139.71 : 145,092.38 = 57,393.09 : x
2. Step 2: Convert to fraction form
   105,139.71/145,092.38 = 57,393.09/x
3. Step 3: Cross multiply
   105,139.71x = 145,092.38 × 57,393.09
4. Step 4: Simplify right side
   105,139.71x = 8,327,299,736.69
5. Step 5: Solve for x
   x = 8,327,299,736.69/105,139.71
6. Step 6: Final answer
   x = 79,202.23