Finding the Fourth Proportional to 1,123.67, 1,685.25 and 430.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.67 : 1,685.25 = 430.32 : x
2. Step 2: Convert to fraction form
   1,123.67/1,685.25 = 430.32/x
3. Step 3: Cross multiply
   1,123.67x = 1,685.25 × 430.32
4. Step 4: Simplify right side
   1,123.67x = 725,196.78
5. Step 5: Solve for x
   x = 725,196.78/1,123.67
6. Step 6: Final answer
   x = 645.39