Finding the Fourth Proportional to 21,105.04, 29,123.40 and 12,152.20

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.04 : 29,123.40 = 12,152.20 : x
2. Step 2: Convert to fraction form
   21,105.04/29,123.40 = 12,152.20/x
3. Step 3: Cross multiply
   21,105.04x = 29,123.40 × 12,152.20
4. Step 4: Simplify right side
   21,105.04x = 353,913,381.48
5. Step 5: Solve for x
   x = 353,913,381.48/21,105.04
6. Step 6: Final answer
   x = 16,769.14