Finding the Fourth Proportional to 1,209.94, 1,669.72 and 712.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,209.94 : 1,669.72 = 712.60 : x
2. Step 2: Convert to fraction form
   1,209.94/1,669.72 = 712.60/x
3. Step 3: Cross multiply
   1,209.94x = 1,669.72 × 712.60
4. Step 4: Simplify right side
   1,209.94x = 1,189,842.47
5. Step 5: Solve for x
   x = 1,189,842.47/1,209.94
6. Step 6: Final answer
   x = 983.39