Finding the Fourth Proportional to 1,223.71, 1,688.43 and 699.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.71 : 1,688.43 = 699.46 : x
2. Step 2: Convert to fraction form
   1,223.71/1,688.43 = 699.46/x
3. Step 3: Cross multiply
   1,223.71x = 1,688.43 × 699.46
4. Step 4: Simplify right side
   1,223.71x = 1,180,989.25
5. Step 5: Solve for x
   x = 1,180,989.25/1,223.71
6. Step 6: Final answer
   x = 965.09