Finding the Fourth Proportional to 3,940.50, 5,437.89 and 2,172.10

Step by Step Solution

1. Step 1: Write the proportion equation
   3,940.50 : 5,437.89 = 2,172.10 : x
2. Step 2: Convert to fraction form
   3,940.50/5,437.89 = 2,172.10/x
3. Step 3: Cross multiply
   3,940.50x = 5,437.89 × 2,172.10
4. Step 4: Simplify right side
   3,940.50x = 11,811,640.87
5. Step 5: Solve for x
   x = 11,811,640.87/3,940.50
6. Step 6: Final answer
   x = 2,997.50