Finding the Fourth Proportional to 21,675.16, 29,796.82 and 18,639.15

Step by Step Solution

1. Step 1: Write the proportion equation
   21,675.16 : 29,796.82 = 18,639.15 : x
2. Step 2: Convert to fraction form
   21,675.16/29,796.82 = 18,639.15/x
3. Step 3: Cross multiply
   21,675.16x = 29,796.82 × 18,639.15
4. Step 4: Simplify right side
   21,675.16x = 555,387,155.32
5. Step 5: Solve for x
   x = 555,387,155.32/21,675.16
6. Step 6: Final answer
   x = 25,623.21