Finding the Fourth Proportional to 2,089.23, 3,131.13 and 855.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,089.23 : 3,131.13 = 855.21 : x
2. Step 2: Convert to fraction form
   2,089.23/3,131.13 = 855.21/x
3. Step 3: Cross multiply
   2,089.23x = 3,131.13 × 855.21
4. Step 4: Simplify right side
   2,089.23x = 2,677,773.69
5. Step 5: Solve for x
   x = 2,677,773.69/2,089.23
6. Step 6: Final answer
   x = 1,281.70