Finding the Fourth Proportional to 1,223.83, 1,688.82 and 699.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.83 : 1,688.82 = 699.86 : x
2. Step 2: Convert to fraction form
   1,223.83/1,688.82 = 699.86/x
3. Step 3: Cross multiply
   1,223.83x = 1,688.82 × 699.86
4. Step 4: Simplify right side
   1,223.83x = 1,181,939.16
5. Step 5: Solve for x
   x = 1,181,939.16/1,223.83
6. Step 6: Final answer
   x = 965.77