Finding the Fourth Proportional to 1,380.27, 1,902.14 and 986.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.27 : 1,902.14 = 986.61 : x
2. Step 2: Convert to fraction form
   1,380.27/1,902.14 = 986.61/x
3. Step 3: Cross multiply
   1,380.27x = 1,902.14 × 986.61
4. Step 4: Simplify right side
   1,380.27x = 1,876,665.41
5. Step 5: Solve for x
   x = 1,876,665.41/1,380.27
6. Step 6: Final answer
   x = 1,359.64