Finding the Fourth Proportional to 1,128.72, 1,693.23 and 435.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.72 : 1,693.23 = 435.56 : x
2. Step 2: Convert to fraction form
   1,128.72/1,693.23 = 435.56/x
3. Step 3: Cross multiply
   1,128.72x = 1,693.23 × 435.56
4. Step 4: Simplify right side
   1,128.72x = 737,494.79
5. Step 5: Solve for x
   x = 737,494.79/1,128.72
6. Step 6: Final answer
   x = 653.39