Finding the Fourth Proportional to 20,718.17, 31,081.89 and 7,570.20

Step by Step Solution

1. Step 1: Write the proportion equation
   20,718.17 : 31,081.89 = 7,570.20 : x
2. Step 2: Convert to fraction form
   20,718.17/31,081.89 = 7,570.20/x
3. Step 3: Cross multiply
   20,718.17x = 31,081.89 × 7,570.20
4. Step 4: Simplify right side
   20,718.17x = 235,296,123.68
5. Step 5: Solve for x
   x = 235,296,123.68/20,718.17
6. Step 6: Final answer
   x = 11,356.99