Finding the Fourth Proportional to 21,123.40, 29,148.32 and 12,623.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.40 : 29,148.32 = 12,623.84 : x
2. Step 2: Convert to fraction form
   21,123.40/29,148.32 = 12,623.84/x
3. Step 3: Cross multiply
   21,123.40x = 29,148.32 × 12,623.84
4. Step 4: Simplify right side
   21,123.40x = 367,963,664.83
5. Step 5: Solve for x
   x = 367,963,664.83/21,123.40
6. Step 6: Final answer
   x = 17,419.72