Finding the Fourth Proportional to 1,003.72, 1,504.74 and 426.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.72 : 1,504.74 = 426.52 : x
2. Step 2: Convert to fraction form
   1,003.72/1,504.74 = 426.52/x
3. Step 3: Cross multiply
   1,003.72x = 1,504.74 × 426.52
4. Step 4: Simplify right side
   1,003.72x = 641,801.70
5. Step 5: Solve for x
   x = 641,801.70/1,003.72
6. Step 6: Final answer
   x = 639.42