Finding the Fourth Proportional to 10,721.08, 14,780.46 and 7,128.64

Step by Step Solution

1. Step 1: Write the proportion equation
   10,721.08 : 14,780.46 = 7,128.64 : x
2. Step 2: Convert to fraction form
   10,721.08/14,780.46 = 7,128.64/x
3. Step 3: Cross multiply
   10,721.08x = 14,780.46 × 7,128.64
4. Step 4: Simplify right side
   10,721.08x = 105,364,578.37
5. Step 5: Solve for x
   x = 105,364,578.37/10,721.08
6. Step 6: Final answer
   x = 9,827.80