Finding the Fourth Proportional to 1,139.92, 1,573.05 and 698.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.92 : 1,573.05 = 698.56 : x
2. Step 2: Convert to fraction form
   1,139.92/1,573.05 = 698.56/x
3. Step 3: Cross multiply
   1,139.92x = 1,573.05 × 698.56
4. Step 4: Simplify right side
   1,139.92x = 1,098,869.81
5. Step 5: Solve for x
   x = 1,098,869.81/1,139.92
6. Step 6: Final answer
   x = 963.99