Finding the Fourth Proportional to 1,393.98, 2,087.19 and 905.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.98 : 2,087.19 = 905.82 : x
2. Step 2: Convert to fraction form
   1,393.98/2,087.19 = 905.82/x
3. Step 3: Cross multiply
   1,393.98x = 2,087.19 × 905.82
4. Step 4: Simplify right side
   1,393.98x = 1,890,618.45
5. Step 5: Solve for x
   x = 1,890,618.45/1,393.98
6. Step 6: Final answer
   x = 1,356.27