Finding the Fourth Proportional to 21,278.30, 29,361.89 and 12,328.67

Step by Step Solution

1. Step 1: Write the proportion equation
   21,278.30 : 29,361.89 = 12,328.67 : x
2. Step 2: Convert to fraction form
   21,278.30/29,361.89 = 12,328.67/x
3. Step 3: Cross multiply
   21,278.30x = 29,361.89 × 12,328.67
4. Step 4: Simplify right side
   21,278.30x = 361,993,156.61
5. Step 5: Solve for x
   x = 361,993,156.61/21,278.30
6. Step 6: Final answer
   x = 17,012.32