Finding the Fourth Proportional to 21,513.78, 29,676.12 and 13,542.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,513.78 : 29,676.12 = 13,542.12 : x
2. Step 2: Convert to fraction form
   21,513.78/29,676.12 = 13,542.12/x
3. Step 3: Cross multiply
   21,513.78x = 29,676.12 × 13,542.12
4. Step 4: Simplify right side
   21,513.78x = 401,877,578.17
5. Step 5: Solve for x
   x = 401,877,578.17/21,513.78
6. Step 6: Final answer
   x = 18,680.01