Finding the Fourth Proportional to 1,128.58, 1,693.20 and 435.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.58 : 1,693.20 = 435.30 : x
2. Step 2: Convert to fraction form
   1,128.58/1,693.20 = 435.30/x
3. Step 3: Cross multiply
   1,128.58x = 1,693.20 × 435.30
4. Step 4: Simplify right side
   1,128.58x = 737,049.96
5. Step 5: Solve for x
   x = 737,049.96/1,128.58
6. Step 6: Final answer
   x = 653.08