Finding the Fourth Proportional to 1,404.39, 2,103.84 and 855.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,404.39 : 2,103.84 = 855.21 : x
2. Step 2: Convert to fraction form
   1,404.39/2,103.84 = 855.21/x
3. Step 3: Cross multiply
   1,404.39x = 2,103.84 × 855.21
4. Step 4: Simplify right side
   1,404.39x = 1,799,225.01
5. Step 5: Solve for x
   x = 1,799,225.01/1,404.39
6. Step 6: Final answer
   x = 1,281.14