Finding the Fourth Proportional to 3,913.71, 5,400.89 and 2,145.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,913.71 : 5,400.89 = 2,145.31 : x
2. Step 2: Convert to fraction form
   3,913.71/5,400.89 = 2,145.31/x
3. Step 3: Cross multiply
   3,913.71x = 5,400.89 × 2,145.31
4. Step 4: Simplify right side
   3,913.71x = 11,586,583.33
5. Step 5: Solve for x
   x = 11,586,583.33/3,913.71
6. Step 6: Final answer
   x = 2,960.51