Finding the Fourth Proportional to 21,828.54, 30,127.01 and 12,878.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,828.54 : 30,127.01 = 12,878.25 : x
2. Step 2: Convert to fraction form
   21,828.54/30,127.01 = 12,878.25/x
3. Step 3: Cross multiply
   21,828.54x = 30,127.01 × 12,878.25
4. Step 4: Simplify right side
   21,828.54x = 387,983,166.53
5. Step 5: Solve for x
   x = 387,983,166.53/21,828.54
6. Step 6: Final answer
   x = 17,774.12