Finding the Fourth Proportional to 1,380.65, 1,903.11 and 1,085.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.65 : 1,903.11 = 1,085.41 : x
2. Step 2: Convert to fraction form
   1,380.65/1,903.11 = 1,085.41/x
3. Step 3: Cross multiply
   1,380.65x = 1,903.11 × 1,085.41
4. Step 4: Simplify right side
   1,380.65x = 2,065,654.63
5. Step 5: Solve for x
   x = 2,065,654.63/1,380.65
6. Step 6: Final answer
   x = 1,496.15