Finding the Fourth Proportional to 2,100.44, 3,149.76 and 639.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.44 : 3,149.76 = 639.32 : x
2. Step 2: Convert to fraction form
   2,100.44/3,149.76 = 639.32/x
3. Step 3: Cross multiply
   2,100.44x = 3,149.76 × 639.32
4. Step 4: Simplify right side
   2,100.44x = 2,013,704.56
5. Step 5: Solve for x
   x = 2,013,704.56/2,100.44
6. Step 6: Final answer
   x = 958.71