Finding the Fourth Proportional to 2,638.42, 3,958.17 and 1,251.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.42 : 3,958.17 = 1,251.91 : x
2. Step 2: Convert to fraction form
   2,638.42/3,958.17 = 1,251.91/x
3. Step 3: Cross multiply
   2,638.42x = 3,958.17 × 1,251.91
4. Step 4: Simplify right side
   2,638.42x = 4,955,250.59
5. Step 5: Solve for x
   x = 4,955,250.59/2,638.42
6. Step 6: Final answer
   x = 1,878.11