Finding the Fourth Proportional to 8,999.76, 12,419.72 and 5,643.88

Step by Step Solution

1. Step 1: Write the proportion equation
   8,999.76 : 12,419.72 = 5,643.88 : x
2. Step 2: Convert to fraction form
   8,999.76/12,419.72 = 5,643.88/x
3. Step 3: Cross multiply
   8,999.76x = 12,419.72 × 5,643.88
4. Step 4: Simplify right side
   8,999.76x = 70,095,409.31
5. Step 5: Solve for x
   x = 70,095,409.31/8,999.76
6. Step 6: Final answer
   x = 7,788.59