Finding the Fourth Proportional to 1,223.52, 1,688.49 and 699.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.52 : 1,688.49 = 699.72 : x
2. Step 2: Convert to fraction form
   1,223.52/1,688.49 = 699.72/x
3. Step 3: Cross multiply
   1,223.52x = 1,688.49 × 699.72
4. Step 4: Simplify right side
   1,223.52x = 1,181,470.22
5. Step 5: Solve for x
   x = 1,181,470.22/1,223.52
6. Step 6: Final answer
   x = 965.63