Finding the Fourth Proportional to 54,084.78, 74,688.12 and 51,139.62

Step by Step Solution

1. Step 1: Write the proportion equation
   54,084.78 : 74,688.12 = 51,139.62 : x
2. Step 2: Convert to fraction form
   54,084.78/74,688.12 = 51,139.62/x
3. Step 3: Cross multiply
   54,084.78x = 74,688.12 × 51,139.62
4. Step 4: Simplify right side
   54,084.78x = 3,819,522,075.31
5. Step 5: Solve for x
   x = 3,819,522,075.31/54,084.78
6. Step 6: Final answer
   x = 70,621.02