Finding the Fourth Proportional to 1,032.71, 1,425.39 and 639.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,032.71 : 1,425.39 = 639.50 : x
2. Step 2: Convert to fraction form
   1,032.71/1,425.39 = 639.50/x
3. Step 3: Cross multiply
   1,032.71x = 1,425.39 × 639.50
4. Step 4: Simplify right side
   1,032.71x = 911,536.91
5. Step 5: Solve for x
   x = 911,536.91/1,032.71
6. Step 6: Final answer
   x = 882.66