Finding the Fourth Proportional to 10,115.34, 13,957.92 and 5,638.80

Step by Step Solution

1. Step 1: Write the proportion equation
   10,115.34 : 13,957.92 = 5,638.80 : x
2. Step 2: Convert to fraction form
   10,115.34/13,957.92 = 5,638.80/x
3. Step 3: Cross multiply
   10,115.34x = 13,957.92 × 5,638.80
4. Step 4: Simplify right side
   10,115.34x = 78,705,919.30
5. Step 5: Solve for x
   x = 78,705,919.30/10,115.34
6. Step 6: Final answer
   x = 7,780.85