Finding the Fourth Proportional to 91,456.30, 128,126.30 and 91,456.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91,456.30 : 128,126.30 = 91,456.30 : x
2. Step 2: Convert to fraction form
   91,456.30/128,126.30 = 91,456.30/x
3. Step 3: Cross multiply
   91,456.30x = 128,126.30 × 91,456.30
4. Step 4: Simplify right side
   91,456.30x = 11,717,957,330.69
5. Step 5: Solve for x
   x = 11,717,957,330.69/91,456.30
6. Step 6: Final answer
   x = 128,126.30