Finding the Fourth Proportional to 12,728.39, 19,085.60 and 4,407.69

Step by Step Solution

1. Step 1: Write the proportion equation
   12,728.39 : 19,085.60 = 4,407.69 : x
2. Step 2: Convert to fraction form
   12,728.39/19,085.60 = 4,407.69/x
3. Step 3: Cross multiply
   12,728.39x = 19,085.60 × 4,407.69
4. Step 4: Simplify right side
   12,728.39x = 84,123,419.28
5. Step 5: Solve for x
   x = 84,123,419.28/12,728.39
6. Step 6: Final answer
   x = 6,609.12