Finding the Fourth Proportional to 3,665.28, 5,057.96 and 2,172.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,665.28 : 5,057.96 = 2,172.31 : x
2. Step 2: Convert to fraction form
   3,665.28/5,057.96 = 2,172.31/x
3. Step 3: Cross multiply
   3,665.28x = 5,057.96 × 2,172.31
4. Step 4: Simplify right side
   3,665.28x = 10,987,460.03
5. Step 5: Solve for x
   x = 10,987,460.03/3,665.28
6. Step 6: Final answer
   x = 2,997.71