Finding the Fourth Proportional to 2,099.42, 3,149.15 and 638.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,099.42 : 3,149.15 = 638.58 : x
2. Step 2: Convert to fraction form
   2,099.42/3,149.15 = 638.58/x
3. Step 3: Cross multiply
   2,099.42x = 3,149.15 × 638.58
4. Step 4: Simplify right side
   2,099.42x = 2,010,992.82
5. Step 5: Solve for x
   x = 2,010,992.82/2,099.42
6. Step 6: Final answer
   x = 957.88