Finding the Fourth Proportional to 1,223.80, 1,688.82 and 699.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.80 : 1,688.82 = 699.82 : x
2. Step 2: Convert to fraction form
   1,223.80/1,688.82 = 699.82/x
3. Step 3: Cross multiply
   1,223.80x = 1,688.82 × 699.82
4. Step 4: Simplify right side
   1,223.80x = 1,181,870.01
5. Step 5: Solve for x
   x = 1,181,870.01/1,223.80
6. Step 6: Final answer
   x = 965.74