Finding the Fourth Proportional to 1,380.44, 1,904.91 and 1,086.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.44 : 1,904.91 = 1,086.41 : x
2. Step 2: Convert to fraction form
   1,380.44/1,904.91 = 1,086.41/x
3. Step 3: Cross multiply
   1,380.44x = 1,904.91 × 1,086.41
4. Step 4: Simplify right side
   1,380.44x = 2,069,513.27
5. Step 5: Solve for x
   x = 2,069,513.27/1,380.44
6. Step 6: Final answer
   x = 1,499.17