Finding the Fourth Proportional to 7,142.86, 9,858.18 and 3,999.25

Step by Step Solution

1. Step 1: Write the proportion equation
   7,142.86 : 9,858.18 = 3,999.25 : x
2. Step 2: Convert to fraction form
   7,142.86/9,858.18 = 3,999.25/x
3. Step 3: Cross multiply
   7,142.86x = 9,858.18 × 3,999.25
4. Step 4: Simplify right side
   7,142.86x = 39,425,326.37
5. Step 5: Solve for x
   x = 39,425,326.37/7,142.86
6. Step 6: Final answer
   x = 5,519.54