Finding the Fourth Proportional to 21,086.76, 29,099.72 and 12,704.88

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.76 : 29,099.72 = 12,704.88 : x
2. Step 2: Convert to fraction form
   21,086.76/29,099.72 = 12,704.88/x
3. Step 3: Cross multiply
   21,086.76x = 29,099.72 × 12,704.88
4. Step 4: Simplify right side
   21,086.76x = 369,708,450.63
5. Step 5: Solve for x
   x = 369,708,450.63/21,086.76
6. Step 6: Final answer
   x = 17,532.73