Finding the Fourth Proportional to 21,665.34, 29,899.53 and 12,709.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,665.34 : 29,899.53 = 12,709.53 : x
2. Step 2: Convert to fraction form
   21,665.34/29,899.53 = 12,709.53/x
3. Step 3: Cross multiply
   21,665.34x = 29,899.53 × 12,709.53
4. Step 4: Simplify right side
   21,665.34x = 380,008,973.52
5. Step 5: Solve for x
   x = 380,008,973.52/21,665.34
6. Step 6: Final answer
   x = 17,539.95