Finding the Fourth Proportional to 9,144.72, 12,619.68 and 5,165.64

Step by Step Solution

1. Step 1: Write the proportion equation
   9,144.72 : 12,619.68 = 5,165.64 : x
2. Step 2: Convert to fraction form
   9,144.72/12,619.68 = 5,165.64/x
3. Step 3: Cross multiply
   9,144.72x = 12,619.68 × 5,165.64
4. Step 4: Simplify right side
   9,144.72x = 65,188,723.80
5. Step 5: Solve for x
   x = 65,188,723.80/9,144.72
6. Step 6: Final answer
   x = 7,128.56