Finding the Fourth Proportional to 1,123.29, 1,685.42 and 430.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.29 : 1,685.42 = 430.17 : x
2. Step 2: Convert to fraction form
   1,123.29/1,685.42 = 430.17/x
3. Step 3: Cross multiply
   1,123.29x = 1,685.42 × 430.17
4. Step 4: Simplify right side
   1,123.29x = 725,017.12
5. Step 5: Solve for x
   x = 725,017.12/1,123.29
6. Step 6: Final answer
   x = 645.44