Finding the Fourth Proportional to 20,884.38, 28,821.59 and 12,391.53

Step by Step Solution

1. Step 1: Write the proportion equation
   20,884.38 : 28,821.59 = 12,391.53 : x
2. Step 2: Convert to fraction form
   20,884.38/28,821.59 = 12,391.53/x
3. Step 3: Cross multiply
   20,884.38x = 28,821.59 × 12,391.53
4. Step 4: Simplify right side
   20,884.38x = 357,143,597.13
5. Step 5: Solve for x
   x = 357,143,597.13/20,884.38
6. Step 6: Final answer
   x = 17,100.99