Finding the Fourth Proportional to 12,049.32, 18,079.48 and 7,128.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,049.32 : 18,079.48 = 7,128.60 : x
2. Step 2: Convert to fraction form
   12,049.32/18,079.48 = 7,128.60/x
3. Step 3: Cross multiply
   12,049.32x = 18,079.48 × 7,128.60
4. Step 4: Simplify right side
   12,049.32x = 128,881,381.13
5. Step 5: Solve for x
   x = 128,881,381.13/12,049.32
6. Step 6: Final answer
   x = 10,696.15