Finding the Fourth Proportional to 20,822.89, 28,756.58 and 13,272.78

Step by Step Solution

1. Step 1: Write the proportion equation
   20,822.89 : 28,756.58 = 13,272.78 : x
2. Step 2: Convert to fraction form
   20,822.89/28,756.58 = 13,272.78/x
3. Step 3: Cross multiply
   20,822.89x = 28,756.58 × 13,272.78
4. Step 4: Simplify right side
   20,822.89x = 381,679,759.89
5. Step 5: Solve for x
   x = 381,679,759.89/20,822.89
6. Step 6: Final answer
   x = 18,329.82