Finding the Fourth Proportional to 3,926.96, 5,419.17 and 2,158.55

Step by Step Solution

1. Step 1: Write the proportion equation
   3,926.96 : 5,419.17 = 2,158.55 : x
2. Step 2: Convert to fraction form
   3,926.96/5,419.17 = 2,158.55/x
3. Step 3: Cross multiply
   3,926.96x = 5,419.17 × 2,158.55
4. Step 4: Simplify right side
   3,926.96x = 11,697,522.31
5. Step 5: Solve for x
   x = 11,697,522.31/3,926.96
6. Step 6: Final answer
   x = 2,978.78