Finding the Fourth Proportional to 1,123.61, 1,684.28 and 430.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.61 : 1,684.28 = 430.10 : x
2. Step 2: Convert to fraction form
   1,123.61/1,684.28 = 430.10/x
3. Step 3: Cross multiply
   1,123.61x = 1,684.28 × 430.10
4. Step 4: Simplify right side
   1,123.61x = 724,406.68
5. Step 5: Solve for x
   x = 724,406.68/1,123.61
6. Step 6: Final answer
   x = 644.71