Finding the Fourth Proportional to 1,139.85, 1,573.12 and 698.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.85 : 1,573.12 = 698.05 : x
2. Step 2: Convert to fraction form
   1,139.85/1,573.12 = 698.05/x
3. Step 3: Cross multiply
   1,139.85x = 1,573.12 × 698.05
4. Step 4: Simplify right side
   1,139.85x = 1,098,116.42
5. Step 5: Solve for x
   x = 1,098,116.42/1,139.85
6. Step 6: Final answer
   x = 963.39