Finding the Fourth Proportional to 1,426.31, 2,139.47 and 400.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,426.31 : 2,139.47 = 400.31 : x
2. Step 2: Convert to fraction form
   1,426.31/2,139.47 = 400.31/x
3. Step 3: Cross multiply
   1,426.31x = 2,139.47 × 400.31
4. Step 4: Simplify right side
   1,426.31x = 856,457.59
5. Step 5: Solve for x
   x = 856,457.59/1,426.31
6. Step 6: Final answer
   x = 600.47