Finding the Fourth Proportional to 1,002.72, 1,503.24 and 425.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.72 : 1,503.24 = 425.52 : x
2. Step 2: Convert to fraction form
   1,002.72/1,503.24 = 425.52/x
3. Step 3: Cross multiply
   1,002.72x = 1,503.24 × 425.52
4. Step 4: Simplify right side
   1,002.72x = 639,658.68
5. Step 5: Solve for x
   x = 639,658.68/1,002.72
6. Step 6: Final answer
   x = 637.92