Finding the Fourth Proportional to 1,002.82, 1,503.87 and 425.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.82 : 1,503.87 = 425.50 : x
2. Step 2: Convert to fraction form
   1,002.82/1,503.87 = 425.50/x
3. Step 3: Cross multiply
   1,002.82x = 1,503.87 × 425.50
4. Step 4: Simplify right side
   1,002.82x = 639,896.69
5. Step 5: Solve for x
   x = 639,896.69/1,002.82
6. Step 6: Final answer
   x = 638.10