Finding the Fourth Proportional to 16,087.20, 21,648.60 and 16,087.20

Step by Step Solution

1. Step 1: Write the proportion equation
   16,087.20 : 21,648.60 = 16,087.20 : x
2. Step 2: Convert to fraction form
   16,087.20/21,648.60 = 16,087.20/x
3. Step 3: Cross multiply
   16,087.20x = 21,648.60 × 16,087.20
4. Step 4: Simplify right side
   16,087.20x = 348,265,357.92
5. Step 5: Solve for x
   x = 348,265,357.92/16,087.20
6. Step 6: Final answer
   x = 21,648.60