Finding the Fourth Proportional to 71,128.96, 106,710.72 and 21,207.04

Step by Step Solution

1. Step 1: Write the proportion equation
   71,128.96 : 106,710.72 = 21,207.04 : x
2. Step 2: Convert to fraction form
   71,128.96/106,710.72 = 21,207.04/x
3. Step 3: Cross multiply
   71,128.96x = 106,710.72 × 21,207.04
4. Step 4: Simplify right side
   71,128.96x = 2,263,018,507.47
5. Step 5: Solve for x
   x = 2,263,018,507.47/71,128.96
6. Step 6: Final answer
   x = 31,815.71