Finding the Fourth Proportional to 91,760.30, 128,308.90 and 91,760.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91,760.30 : 128,308.90 = 91,760.30 : x
2. Step 2: Convert to fraction form
   91,760.30/128,308.90 = 91,760.30/x
3. Step 3: Cross multiply
   91,760.30x = 128,308.90 × 91,760.30
4. Step 4: Simplify right side
   91,760.30x = 11,773,663,156.67
5. Step 5: Solve for x
   x = 11,773,663,156.67/91,760.30
6. Step 6: Final answer
   x = 128,308.90