Finding the Fourth Proportional to 10,120.40, 13,965.60 and 5,644.05

Step by Step Solution

1. Step 1: Write the proportion equation
   10,120.40 : 13,965.60 = 5,644.05 : x
2. Step 2: Convert to fraction form
   10,120.40/13,965.60 = 5,644.05/x
3. Step 3: Cross multiply
   10,120.40x = 13,965.60 × 5,644.05
4. Step 4: Simplify right side
   10,120.40x = 78,822,513.47
5. Step 5: Solve for x
   x = 78,822,513.47/10,120.40
6. Step 6: Final answer
   x = 7,788.48