Finding the Fourth Proportional to 3,978.42, 5,447.78 and 3,821.58

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.42 : 5,447.78 = 3,821.58 : x
2. Step 2: Convert to fraction form
   3,978.42/5,447.78 = 3,821.58/x
3. Step 3: Cross multiply
   3,978.42x = 5,447.78 × 3,821.58
4. Step 4: Simplify right side
   3,978.42x = 20,819,109.41
5. Step 5: Solve for x
   x = 20,819,109.41/3,978.42
6. Step 6: Final answer
   x = 5,233.00