Finding the Fourth Proportional to 1,019.61, 1,407.12 and 577.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.61 : 1,407.12 = 577.35 : x
2. Step 2: Convert to fraction form
   1,019.61/1,407.12 = 577.35/x
3. Step 3: Cross multiply
   1,019.61x = 1,407.12 × 577.35
4. Step 4: Simplify right side
   1,019.61x = 812,400.73
5. Step 5: Solve for x
   x = 812,400.73/1,019.61
6. Step 6: Final answer
   x = 796.78