Finding the Fourth Proportional to 2,086.84, 3,129.72 and 854.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.84 : 3,129.72 = 854.02 : x
2. Step 2: Convert to fraction form
   2,086.84/3,129.72 = 854.02/x
3. Step 3: Cross multiply
   2,086.84x = 3,129.72 × 854.02
4. Step 4: Simplify right side
   2,086.84x = 2,672,843.47
5. Step 5: Solve for x
   x = 2,672,843.47/2,086.84
6. Step 6: Final answer
   x = 1,280.81