Finding the Fourth Proportional to 91,707.30, 128,234.70 and 91,707.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91,707.30 : 128,234.70 = 91,707.30 : x
2. Step 2: Convert to fraction form
   91,707.30/128,234.70 = 91,707.30/x
3. Step 3: Cross multiply
   91,707.30x = 128,234.70 × 91,707.30
4. Step 4: Simplify right side
   91,707.30x = 11,760,058,103.31
5. Step 5: Solve for x
   x = 11,760,058,103.31/91,707.30
6. Step 6: Final answer
   x = 128,234.70