Finding the Fourth Proportional to 3,665.56, 5,057.76 and 2,173.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,665.56 : 5,057.76 = 2,173.20 : x
2. Step 2: Convert to fraction form
   3,665.56/5,057.76 = 2,173.20/x
3. Step 3: Cross multiply
   3,665.56x = 5,057.76 × 2,173.20
4. Step 4: Simplify right side
   3,665.56x = 10,991,524.03
5. Step 5: Solve for x
   x = 10,991,524.03/3,665.56
6. Step 6: Final answer
   x = 2,998.59