Finding the Fourth Proportional to 105,508.78, 145,605.40 and 57,766.56

Step by Step Solution

1. Step 1: Write the proportion equation
   105,508.78 : 145,605.40 = 57,766.56 : x
2. Step 2: Convert to fraction form
   105,508.78/145,605.40 = 57,766.56/x
3. Step 3: Cross multiply
   105,508.78x = 145,605.40 × 57,766.56
4. Step 4: Simplify right side
   105,508.78x = 8,411,123,075.42
5. Step 5: Solve for x
   x = 8,411,123,075.42/105,508.78
6. Step 6: Final answer
   x = 79,719.65