Finding the Fourth Proportional to 1,223.94, 1,688.76 and 699.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.94 : 1,688.76 = 699.96 : x
2. Step 2: Convert to fraction form
   1,223.94/1,688.76 = 699.96/x
3. Step 3: Cross multiply
   1,223.94x = 1,688.76 × 699.96
4. Step 4: Simplify right side
   1,223.94x = 1,182,064.45
5. Step 5: Solve for x
   x = 1,182,064.45/1,223.94
6. Step 6: Final answer
   x = 965.79