Finding the Fourth Proportional to 10,116.70, 13,957.77 and 5,639.57

Step by Step Solution

1. Step 1: Write the proportion equation
   10,116.70 : 13,957.77 = 5,639.57 : x
2. Step 2: Convert to fraction form
   10,116.70/13,957.77 = 5,639.57/x
3. Step 3: Cross multiply
   10,116.70x = 13,957.77 × 5,639.57
4. Step 4: Simplify right side
   10,116.70x = 78,715,871.45
5. Step 5: Solve for x
   x = 78,715,871.45/10,116.70
6. Step 6: Final answer
   x = 7,780.79