Finding the Fourth Proportional to 1,039.50, 1,559.34 and 423.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.50 : 1,559.34 = 423.25 : x
2. Step 2: Convert to fraction form
   1,039.50/1,559.34 = 423.25/x
3. Step 3: Cross multiply
   1,039.50x = 1,559.34 × 423.25
4. Step 4: Simplify right side
   1,039.50x = 659,986.76
5. Step 5: Solve for x
   x = 659,986.76/1,039.50
6. Step 6: Final answer
   x = 634.91