Finding the Fourth Proportional to 8,999.91, 12,411.82 and 5,643.09

Step by Step Solution

1. Step 1: Write the proportion equation
   8,999.91 : 12,411.82 = 5,643.09 : x
2. Step 2: Convert to fraction form
   8,999.91/12,411.82 = 5,643.09/x
3. Step 3: Cross multiply
   8,999.91x = 12,411.82 × 5,643.09
4. Step 4: Simplify right side
   8,999.91x = 70,041,017.32
5. Step 5: Solve for x
   x = 70,041,017.32/8,999.91
6. Step 6: Final answer
   x = 7,782.41