Finding the Fourth Proportional to 105,081.98, 145,012.92 and 57,335.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,081.98 : 145,012.92 = 57,335.30 : x
2. Step 2: Convert to fraction form
   105,081.98/145,012.92 = 57,335.30/x
3. Step 3: Cross multiply
   105,081.98x = 145,012.92 × 57,335.30
4. Step 4: Simplify right side
   105,081.98x = 8,314,359,272.08
5. Step 5: Solve for x
   x = 8,314,359,272.08/105,081.98
6. Step 6: Final answer
   x = 79,122.60