Finding the Fourth Proportional to 1,288.94, 1,778.72 and 699.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.94 : 1,778.72 = 699.46 : x
2. Step 2: Convert to fraction form
   1,288.94/1,778.72 = 699.46/x
3. Step 3: Cross multiply
   1,288.94x = 1,778.72 × 699.46
4. Step 4: Simplify right side
   1,288.94x = 1,244,135.55
5. Step 5: Solve for x
   x = 1,244,135.55/1,288.94
6. Step 6: Final answer
   x = 965.24