Finding the Fourth Proportional to 5,451.13, 8,128.82 and 5,404.21

Step by Step Solution

1. Step 1: Write the proportion equation
   5,451.13 : 8,128.82 = 5,404.21 : x
2. Step 2: Convert to fraction form
   5,451.13/8,128.82 = 5,404.21/x
3. Step 3: Cross multiply
   5,451.13x = 8,128.82 × 5,404.21
4. Step 4: Simplify right side
   5,451.13x = 43,929,850.33
5. Step 5: Solve for x
   x = 43,929,850.33/5,451.13
6. Step 6: Final answer
   x = 8,058.85