Finding the Fourth Proportional to 1,397.31, 1,927.17 and 1,240.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.31 : 1,927.17 = 1,240.05 : x
2. Step 2: Convert to fraction form
   1,397.31/1,927.17 = 1,240.05/x
3. Step 3: Cross multiply
   1,397.31x = 1,927.17 × 1,240.05
4. Step 4: Simplify right side
   1,397.31x = 2,389,787.16
5. Step 5: Solve for x
   x = 2,389,787.16/1,397.31
6. Step 6: Final answer
   x = 1,710.28