Finding the Fourth Proportional to 1,019.20, 1,406.56 and 577.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.20 : 1,406.56 = 577.12 : x
2. Step 2: Convert to fraction form
   1,019.20/1,406.56 = 577.12/x
3. Step 3: Cross multiply
   1,019.20x = 1,406.56 × 577.12
4. Step 4: Simplify right side
   1,019.20x = 811,753.91
5. Step 5: Solve for x
   x = 811,753.91/1,019.20
6. Step 6: Final answer
   x = 796.46