Finding the Fourth Proportional to 21,559.82, 29,752.53 and 12,128.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,559.82 : 29,752.53 = 12,128.38 : x
2. Step 2: Convert to fraction form
   21,559.82/29,752.53 = 12,128.38/x
3. Step 3: Cross multiply
   21,559.82x = 29,752.53 × 12,128.38
4. Step 4: Simplify right side
   21,559.82x = 360,849,915.42
5. Step 5: Solve for x
   x = 360,849,915.42/21,559.82
6. Step 6: Final answer
   x = 16,737.15