Finding the Fourth Proportional to 1,287.52, 1,774.90 and 789.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.52 : 1,774.90 = 789.84 : x
2. Step 2: Convert to fraction form
   1,287.52/1,774.90 = 789.84/x
3. Step 3: Cross multiply
   1,287.52x = 1,774.90 × 789.84
4. Step 4: Simplify right side
   1,287.52x = 1,401,887.02
5. Step 5: Solve for x
   x = 1,401,887.02/1,287.52
6. Step 6: Final answer
   x = 1,088.83