Finding the Fourth Proportional to 21,510.53, 29,686.64 and 12,436.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,510.53 : 29,686.64 = 12,436.28 : x
2. Step 2: Convert to fraction form
   21,510.53/29,686.64 = 12,436.28/x
3. Step 3: Cross multiply
   21,510.53x = 29,686.64 × 12,436.28
4. Step 4: Simplify right side
   21,510.53x = 369,191,156.68
5. Step 5: Solve for x
   x = 369,191,156.68/21,510.53
6. Step 6: Final answer
   x = 17,163.28