Finding the Fourth Proportional to 7,209.12, 10,809.96 and 5,127.78

Step by Step Solution

1. Step 1: Write the proportion equation
   7,209.12 : 10,809.96 = 5,127.78 : x
2. Step 2: Convert to fraction form
   7,209.12/10,809.96 = 5,127.78/x
3. Step 3: Cross multiply
   7,209.12x = 10,809.96 × 5,127.78
4. Step 4: Simplify right side
   7,209.12x = 55,431,096.69
5. Step 5: Solve for x
   x = 55,431,096.69/7,209.12
6. Step 6: Final answer
   x = 7,689.02