Finding the Fourth Proportional to 2,100.42, 3,149.43 and 639.14

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.42 : 3,149.43 = 639.14 : x
2. Step 2: Convert to fraction form
   2,100.42/3,149.43 = 639.14/x
3. Step 3: Cross multiply
   2,100.42x = 3,149.43 × 639.14
4. Step 4: Simplify right side
   2,100.42x = 2,012,926.69
5. Step 5: Solve for x
   x = 2,012,926.69/2,100.42
6. Step 6: Final answer
   x = 958.34