Finding the Fourth Proportional to 21,585.72, 29,773.72 and 13,621.24

Step by Step Solution

1. Step 1: Write the proportion equation
   21,585.72 : 29,773.72 = 13,621.24 : x
2. Step 2: Convert to fraction form
   21,585.72/29,773.72 = 13,621.24/x
3. Step 3: Cross multiply
   21,585.72x = 29,773.72 × 13,621.24
4. Step 4: Simplify right side
   21,585.72x = 405,554,985.81
5. Step 5: Solve for x
   x = 405,554,985.81/21,585.72
6. Step 6: Final answer
   x = 18,788.11