Finding the Fourth Proportional to 91,700.30, 128,467.90 and 91,700.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91,700.30 : 128,467.90 = 91,700.30 : x
2. Step 2: Convert to fraction form
   91,700.30/128,467.90 = 91,700.30/x
3. Step 3: Cross multiply
   91,700.30x = 128,467.90 × 91,700.30
4. Step 4: Simplify right side
   91,700.30x = 11,780,544,970.37
5. Step 5: Solve for x
   x = 11,780,544,970.37/91,700.30
6. Step 6: Final answer
   x = 128,467.90