Finding the Fourth Proportional to 21,007.04, 31,513.68 and 7,680.71

Step by Step Solution

1. Step 1: Write the proportion equation
   21,007.04 : 31,513.68 = 7,680.71 : x
2. Step 2: Convert to fraction form
   21,007.04/31,513.68 = 7,680.71/x
3. Step 3: Cross multiply
   21,007.04x = 31,513.68 × 7,680.71
4. Step 4: Simplify right side
   21,007.04x = 242,047,279.54
5. Step 5: Solve for x
   x = 242,047,279.54/21,007.04
6. Step 6: Final answer
   x = 11,522.20