Finding the Fourth Proportional to 15,022.56, 22,519.89 and 7,128.78

Step by Step Solution

1. Step 1: Write the proportion equation
   15,022.56 : 22,519.89 = 7,128.78 : x
2. Step 2: Convert to fraction form
   15,022.56/22,519.89 = 7,128.78/x
3. Step 3: Cross multiply
   15,022.56x = 22,519.89 × 7,128.78
4. Step 4: Simplify right side
   15,022.56x = 160,539,341.43
5. Step 5: Solve for x
   x = 160,539,341.43/15,022.56
6. Step 6: Final answer
   x = 10,686.55