Finding the Fourth Proportional to 2,099.99, 3,150.45 and 639.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,099.99 : 3,150.45 = 639.25 : x
2. Step 2: Convert to fraction form
   2,099.99/3,150.45 = 639.25/x
3. Step 3: Cross multiply
   2,099.99x = 3,150.45 × 639.25
4. Step 4: Simplify right side
   2,099.99x = 2,013,927.30
5. Step 5: Solve for x
   x = 2,013,927.30/2,099.99
6. Step 6: Final answer
   x = 959.02