Finding the Fourth Proportional to 21,099.58, 29,130.05 and 13,152.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,099.58 : 29,130.05 = 13,152.57 : x
2. Step 2: Convert to fraction form
   21,099.58/29,130.05 = 13,152.57/x
3. Step 3: Cross multiply
   21,099.58x = 29,130.05 × 13,152.57
4. Step 4: Simplify right side
   21,099.58x = 383,135,054.61
5. Step 5: Solve for x
   x = 383,135,054.61/21,099.58
6. Step 6: Final answer
   x = 18,158.42