Finding the Fourth Proportional to 21,160.24, 31,741.94 and 7,120.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,160.24 : 31,741.94 = 7,120.31 : x
2. Step 2: Convert to fraction form
   21,160.24/31,741.94 = 7,120.31/x
3. Step 3: Cross multiply
   21,160.24x = 31,741.94 × 7,120.31
4. Step 4: Simplify right side
   21,160.24x = 226,012,311.89
5. Step 5: Solve for x
   x = 226,012,311.89/21,160.24
6. Step 6: Final answer
   x = 10,680.99