Finding the Fourth Proportional to 1,019.21, 1,406.52 and 553.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.21 : 1,406.52 = 553.46 : x
2. Step 2: Convert to fraction form
   1,019.21/1,406.52 = 553.46/x
3. Step 3: Cross multiply
   1,019.21x = 1,406.52 × 553.46
4. Step 4: Simplify right side
   1,019.21x = 778,445.53
5. Step 5: Solve for x
   x = 778,445.53/1,019.21
6. Step 6: Final answer
   x = 763.78