Finding the Fourth Proportional to 1,019.73, 1,407.21 and 553.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.73 : 1,407.21 = 553.98 : x
2. Step 2: Convert to fraction form
   1,019.73/1,407.21 = 553.98/x
3. Step 3: Cross multiply
   1,019.73x = 1,407.21 × 553.98
4. Step 4: Simplify right side
   1,019.73x = 779,566.20
5. Step 5: Solve for x
   x = 779,566.20/1,019.73
6. Step 6: Final answer
   x = 764.48