Finding the Fourth Proportional to 1,287.35, 1,776.59 and 712.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.35 : 1,776.59 = 712.46 : x
2. Step 2: Convert to fraction form
   1,287.35/1,776.59 = 712.46/x
3. Step 3: Cross multiply
   1,287.35x = 1,776.59 × 712.46
4. Step 4: Simplify right side
   1,287.35x = 1,265,745.87
5. Step 5: Solve for x
   x = 1,265,745.87/1,287.35
6. Step 6: Final answer
   x = 983.21