Finding the Fourth Proportional to 1,020.72, 1,406.55 and 725.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.72 : 1,406.55 = 725.49 : x
2. Step 2: Convert to fraction form
   1,020.72/1,406.55 = 725.49/x
3. Step 3: Cross multiply
   1,020.72x = 1,406.55 × 725.49
4. Step 4: Simplify right side
   1,020.72x = 1,020,437.96
5. Step 5: Solve for x
   x = 1,020,437.96/1,020.72
6. Step 6: Final answer
   x = 999.72