Finding the Fourth Proportional to 1,404.21, 2,104.72 and 855.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,404.21 : 2,104.72 = 855.18 : x
2. Step 2: Convert to fraction form
   1,404.21/2,104.72 = 855.18/x
3. Step 3: Cross multiply
   1,404.21x = 2,104.72 × 855.18
4. Step 4: Simplify right side
   1,404.21x = 1,799,912.31
5. Step 5: Solve for x
   x = 1,799,912.31/1,404.21
6. Step 6: Final answer
   x = 1,281.79