Finding the Fourth Proportional to 1,021.45, 1,530.15 and 558.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.45 : 1,530.15 = 558.55 : x
2. Step 2: Convert to fraction form
   1,021.45/1,530.15 = 558.55/x
3. Step 3: Cross multiply
   1,021.45x = 1,530.15 × 558.55
4. Step 4: Simplify right side
   1,021.45x = 854,665.28
5. Step 5: Solve for x
   x = 854,665.28/1,021.45
6. Step 6: Final answer
   x = 836.72