Finding the Fourth Proportional to 1,019.35, 1,406.69 and 553.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.35 : 1,406.69 = 553.60 : x
2. Step 2: Convert to fraction form
   1,019.35/1,406.69 = 553.60/x
3. Step 3: Cross multiply
   1,019.35x = 1,406.69 × 553.60
4. Step 4: Simplify right side
   1,019.35x = 778,741.45
5. Step 5: Solve for x
   x = 778,741.45/1,019.35
6. Step 6: Final answer
   x = 763.96