Finding the Fourth Proportional to 1,109.50, 1,664.33 and 425.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.50 : 1,664.33 = 425.50 : x
2. Step 2: Convert to fraction form
   1,109.50/1,664.33 = 425.50/x
3. Step 3: Cross multiply
   1,109.50x = 1,664.33 × 425.50
4. Step 4: Simplify right side
   1,109.50x = 708,172.42
5. Step 5: Solve for x
   x = 708,172.42/1,109.50
6. Step 6: Final answer
   x = 638.28