Finding the Fourth Proportional to 21,786.56, 30,065.45 and 12,355.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,786.56 : 30,065.45 = 12,355.12 : x
2. Step 2: Convert to fraction form
   21,786.56/30,065.45 = 12,355.12/x
3. Step 3: Cross multiply
   21,786.56x = 30,065.45 × 12,355.12
4. Step 4: Simplify right side
   21,786.56x = 371,462,242.60
5. Step 5: Solve for x
   x = 371,462,242.60/21,786.56
6. Step 6: Final answer
   x = 17,050.06