Finding the Fourth Proportional to 10,138.72, 13,996.88 and 7,157.28

Step by Step Solution

1. Step 1: Write the proportion equation
   10,138.72 : 13,996.88 = 7,157.28 : x
2. Step 2: Convert to fraction form
   10,138.72/13,996.88 = 7,157.28/x
3. Step 3: Cross multiply
   10,138.72x = 13,996.88 × 7,157.28
4. Step 4: Simplify right side
   10,138.72x = 100,179,589.29
5. Step 5: Solve for x
   x = 100,179,589.29/10,138.72
6. Step 6: Final answer
   x = 9,880.89