Finding the Fourth Proportional to 21,105.45, 29,124.54 and 12,608.91

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.45 : 29,124.54 = 12,608.91 : x
2. Step 2: Convert to fraction form
   21,105.45/29,124.54 = 12,608.91/x
3. Step 3: Cross multiply
   21,105.45x = 29,124.54 × 12,608.91
4. Step 4: Simplify right side
   21,105.45x = 367,228,703.65
5. Step 5: Solve for x
   x = 367,228,703.65/21,105.45
6. Step 6: Final answer
   x = 17,399.71