Finding the Fourth Proportional to 5,172.89, 7,138.61 and 2,815.03

Step by Step Solution

1. Step 1: Write the proportion equation
   5,172.89 : 7,138.61 = 2,815.03 : x
2. Step 2: Convert to fraction form
   5,172.89/7,138.61 = 2,815.03/x
3. Step 3: Cross multiply
   5,172.89x = 7,138.61 × 2,815.03
4. Step 4: Simplify right side
   5,172.89x = 20,095,401.31
5. Step 5: Solve for x
   x = 20,095,401.31/5,172.89
6. Step 6: Final answer
   x = 3,884.75