Finding the Fourth Proportional to 21,786.17, 30,066.39 and 12,355.34

Step by Step Solution

1. Step 1: Write the proportion equation
   21,786.17 : 30,066.39 = 12,355.34 : x
2. Step 2: Convert to fraction form
   21,786.17/30,066.39 = 12,355.34/x
3. Step 3: Cross multiply
   21,786.17x = 30,066.39 × 12,355.34
4. Step 4: Simplify right side
   21,786.17x = 371,480,320.69
5. Step 5: Solve for x
   x = 371,480,320.69/21,786.17
6. Step 6: Final answer
   x = 17,051.20