Finding the Fourth Proportional to 21,018.24, 29,018.68 and 13,071.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,018.24 : 29,018.68 = 13,071.28 : x
2. Step 2: Convert to fraction form
   21,018.24/29,018.68 = 13,071.28/x
3. Step 3: Cross multiply
   21,018.24x = 29,018.68 × 13,071.28
4. Step 4: Simplify right side
   21,018.24x = 379,311,291.51
5. Step 5: Solve for x
   x = 379,311,291.51/21,018.24
6. Step 6: Final answer
   x = 18,046.77