Finding the Fourth Proportional to 21,104.01, 29,123.28 and 12,720.51

Step by Step Solution

1. Step 1: Write the proportion equation
   21,104.01 : 29,123.28 = 12,720.51 : x
2. Step 2: Convert to fraction form
   21,104.01/29,123.28 = 12,720.51/x
3. Step 3: Cross multiply
   21,104.01x = 29,123.28 × 12,720.51
4. Step 4: Simplify right side
   21,104.01x = 370,462,974.47
5. Step 5: Solve for x
   x = 370,462,974.47/21,104.01
6. Step 6: Final answer
   x = 17,554.15