Finding the Fourth Proportional to 1,123.57, 1,684.18 and 430.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.57 : 1,684.18 = 430.17 : x
2. Step 2: Convert to fraction form
   1,123.57/1,684.18 = 430.17/x
3. Step 3: Cross multiply
   1,123.57x = 1,684.18 × 430.17
4. Step 4: Simplify right side
   1,123.57x = 724,483.71
5. Step 5: Solve for x
   x = 724,483.71/1,123.57
6. Step 6: Final answer
   x = 644.81