Finding the Fourth Proportional to 21,144.40, 31,718.76 and 7,290.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,144.40 : 31,718.76 = 7,290.16 : x
2. Step 2: Convert to fraction form
   21,144.40/31,718.76 = 7,290.16/x
3. Step 3: Cross multiply
   21,144.40x = 31,718.76 × 7,290.16
4. Step 4: Simplify right side
   21,144.40x = 231,234,835.40
5. Step 5: Solve for x
   x = 231,234,835.40/21,144.40
6. Step 6: Final answer
   x = 10,935.98