Finding the Fourth Proportional to 19,664.70, 27,105.69 and 13,289.31

Step by Step Solution

1. Step 1: Write the proportion equation
   19,664.70 : 27,105.69 = 13,289.31 : x
2. Step 2: Convert to fraction form
   19,664.70/27,105.69 = 13,289.31/x
3. Step 3: Cross multiply
   19,664.70x = 27,105.69 × 13,289.31
4. Step 4: Simplify right side
   19,664.70x = 360,215,917.17
5. Step 5: Solve for x
   x = 360,215,917.17/19,664.70
6. Step 6: Final answer
   x = 18,317.90