Finding the Fourth Proportional to 21,087.42, 29,100.56 and 12,012.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,087.42 : 29,100.56 = 12,012.78 : x
2. Step 2: Convert to fraction form
   21,087.42/29,100.56 = 12,012.78/x
3. Step 3: Cross multiply
   21,087.42x = 29,100.56 × 12,012.78
4. Step 4: Simplify right side
   21,087.42x = 349,578,625.16
5. Step 5: Solve for x
   x = 349,578,625.16/21,087.42
6. Step 6: Final answer
   x = 16,577.59