Finding the Fourth Proportional to 28,540.42, 42,828.45 and 20,536

Step by Step Solution

1. Step 1: Write the proportion equation
   28,540.42 : 42,828.45 = 20,536 : x
2. Step 2: Convert to fraction form
   28,540.42/42,828.45 = 20,536/x
3. Step 3: Cross multiply
   28,540.42x = 42,828.45 × 20,536
4. Step 4: Simplify right side
   28,540.42x = 879,525,049.20
5. Step 5: Solve for x
   x = 879,525,049.20/28,540.42
6. Step 6: Final answer
   x = 30,816.82