Finding the Fourth Proportional to 2,100.18, 3,150.22 and 639.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.18 : 3,150.22 = 639.32 : x
2. Step 2: Convert to fraction form
   2,100.18/3,150.22 = 639.32/x
3. Step 3: Cross multiply
   2,100.18x = 3,150.22 × 639.32
4. Step 4: Simplify right side
   2,100.18x = 2,013,998.65
5. Step 5: Solve for x
   x = 2,013,998.65/2,100.18
6. Step 6: Final answer
   x = 958.96