Finding the Fourth Proportional to 6,619.98, 9,131.56 and 3,929.42

Step by Step Solution

1. Step 1: Write the proportion equation
   6,619.98 : 9,131.56 = 3,929.42 : x
2. Step 2: Convert to fraction form
   6,619.98/9,131.56 = 3,929.42/x
3. Step 3: Cross multiply
   6,619.98x = 9,131.56 × 3,929.42
4. Step 4: Simplify right side
   6,619.98x = 35,881,757.32
5. Step 5: Solve for x
   x = 35,881,757.32/6,619.98
6. Step 6: Final answer
   x = 5,420.22