Finding the Fourth Proportional to 872.72, 1,306.72 and 698.56

Step by Step Solution

1. Step 1: Write the proportion equation
   872.72 : 1,306.72 = 698.56 : x
2. Step 2: Convert to fraction form
   872.72/1,306.72 = 698.56/x
3. Step 3: Cross multiply
   872.72x = 1,306.72 × 698.56
4. Step 4: Simplify right side
   872.72x = 912,822.32
5. Step 5: Solve for x
   x = 912,822.32/872.72
6. Step 6: Final answer
   x = 1,045.95