Finding the Fourth Proportional to 21,642.30, 29,866.59 and 12,695.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,642.30 : 29,866.59 = 12,695.10 : x
2. Step 2: Convert to fraction form
   21,642.30/29,866.59 = 12,695.10/x
3. Step 3: Cross multiply
   21,642.30x = 29,866.59 × 12,695.10
4. Step 4: Simplify right side
   21,642.30x = 379,159,346.71
5. Step 5: Solve for x
   x = 379,159,346.71/21,642.30
6. Step 6: Final answer
   x = 17,519.36