Finding the Fourth Proportional to 91,722.10, 128,148.50 and 91,722.10

Step by Step Solution

1. Step 1: Write the proportion equation
   91,722.10 : 128,148.50 = 91,722.10 : x
2. Step 2: Convert to fraction form
   91,722.10/128,148.50 = 91,722.10/x
3. Step 3: Cross multiply
   91,722.10x = 128,148.50 × 91,722.10
4. Step 4: Simplify right side
   91,722.10x = 11,754,049,531.85
5. Step 5: Solve for x
   x = 11,754,049,531.85/91,722.10
6. Step 6: Final answer
   x = 128,148.50