Finding the Fourth Proportional to 3,926.42, 5,418.34 and 2,157.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,926.42 : 5,418.34 = 2,157.86 : x
2. Step 2: Convert to fraction form
   3,926.42/5,418.34 = 2,157.86/x
3. Step 3: Cross multiply
   3,926.42x = 5,418.34 × 2,157.86
4. Step 4: Simplify right side
   3,926.42x = 11,692,019.15
5. Step 5: Solve for x
   x = 11,692,019.15/3,926.42
6. Step 6: Final answer
   x = 2,977.78