Finding the Fourth Proportional to 21,123.54, 29,148.49 and 12,623.97

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.54 : 29,148.49 = 12,623.97 : x
2. Step 2: Convert to fraction form
   21,123.54/29,148.49 = 12,623.97/x
3. Step 3: Cross multiply
   21,123.54x = 29,148.49 × 12,623.97
4. Step 4: Simplify right side
   21,123.54x = 367,969,663.31
5. Step 5: Solve for x
   x = 367,969,663.31/21,123.54
6. Step 6: Final answer
   x = 17,419.89