Finding the Fourth Proportional to 1,257.78, 1,735.72 and 698.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,257.78 : 1,735.72 = 698.22 : x
2. Step 2: Convert to fraction form
   1,257.78/1,735.72 = 698.22/x
3. Step 3: Cross multiply
   1,257.78x = 1,735.72 × 698.22
4. Step 4: Simplify right side
   1,257.78x = 1,211,914.42
5. Step 5: Solve for x
   x = 1,211,914.42/1,257.78
6. Step 6: Final answer
   x = 963.53