Finding the Fourth Proportional to 28,105.20, 42,158.52 and 13,310.64

Step by Step Solution

1. Step 1: Write the proportion equation
   28,105.20 : 42,158.52 = 13,310.64 : x
2. Step 2: Convert to fraction form
   28,105.20/42,158.52 = 13,310.64/x
3. Step 3: Cross multiply
   28,105.20x = 42,158.52 × 13,310.64
4. Step 4: Simplify right side
   28,105.20x = 561,156,882.65
5. Step 5: Solve for x
   x = 561,156,882.65/28,105.20
6. Step 6: Final answer
   x = 19,966.30