Finding the Fourth Proportional to 21,336.42, 29,449.53 and 12,959.94

Step by Step Solution

1. Step 1: Write the proportion equation
   21,336.42 : 29,449.53 = 12,959.94 : x
2. Step 2: Convert to fraction form
   21,336.42/29,449.53 = 12,959.94/x
3. Step 3: Cross multiply
   21,336.42x = 29,449.53 × 12,959.94
4. Step 4: Simplify right side
   21,336.42x = 381,664,141.83
5. Step 5: Solve for x
   x = 381,664,141.83/21,336.42
6. Step 6: Final answer
   x = 17,887.92