Finding the Fourth Proportional to 1,019.80, 1,407.24 and 577.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.80 : 1,407.24 = 577.60 : x
2. Step 2: Convert to fraction form
   1,019.80/1,407.24 = 577.60/x
3. Step 3: Cross multiply
   1,019.80x = 1,407.24 × 577.60
4. Step 4: Simplify right side
   1,019.80x = 812,821.82
5. Step 5: Solve for x
   x = 812,821.82/1,019.80
6. Step 6: Final answer
   x = 797.04