Finding the Fourth Proportional to 20,210.69, 27,880.72 and 13,505.31

Step by Step Solution

1. Step 1: Write the proportion equation
   20,210.69 : 27,880.72 = 13,505.31 : x
2. Step 2: Convert to fraction form
   20,210.69/27,880.72 = 13,505.31/x
3. Step 3: Cross multiply
   20,210.69x = 27,880.72 × 13,505.31
4. Step 4: Simplify right side
   20,210.69x = 376,537,559.69
5. Step 5: Solve for x
   x = 376,537,559.69/20,210.69
6. Step 6: Final answer
   x = 18,630.62