Finding the Fourth Proportional to 2,488.15, 3,732.21 and 639.27

Step by Step Solution

1. Step 1: Write the proportion equation
   2,488.15 : 3,732.21 = 639.27 : x
2. Step 2: Convert to fraction form
   2,488.15/3,732.21 = 639.27/x
3. Step 3: Cross multiply
   2,488.15x = 3,732.21 × 639.27
4. Step 4: Simplify right side
   2,488.15x = 2,385,889.89
5. Step 5: Solve for x
   x = 2,385,889.89/2,488.15
6. Step 6: Final answer
   x = 958.90