Finding the Fourth Proportional to 21,860.04, 30,165.71 and 12,904.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,860.04 : 30,165.71 = 12,904.28 : x
2. Step 2: Convert to fraction form
   21,860.04/30,165.71 = 12,904.28/x
3. Step 3: Cross multiply
   21,860.04x = 30,165.71 × 12,904.28
4. Step 4: Simplify right side
   21,860.04x = 389,266,552.89
5. Step 5: Solve for x
   x = 389,266,552.89/21,860.04
6. Step 6: Final answer
   x = 17,807.22