Finding the Fourth Proportional to 10,816.20, 16,222.91 and 3,420

Step by Step Solution

1. Step 1: Write the proportion equation
   10,816.20 : 16,222.91 = 3,420 : x
2. Step 2: Convert to fraction form
   10,816.20/16,222.91 = 3,420/x
3. Step 3: Cross multiply
   10,816.20x = 16,222.91 × 3,420
4. Step 4: Simplify right side
   10,816.20x = 55,482,335.10
5. Step 5: Solve for x
   x = 55,482,335.10/10,816.20
6. Step 6: Final answer
   x = 5,129.56