Finding the Fourth Proportional to 64,967.10, 91,128.90 and 64,967.10

Step by Step Solution

1. Step 1: Write the proportion equation
   64,967.10 : 91,128.90 = 64,967.10 : x
2. Step 2: Convert to fraction form
   64,967.10/91,128.90 = 64,967.10/x
3. Step 3: Cross multiply
   64,967.10x = 91,128.90 × 64,967.10
4. Step 4: Simplify right side
   64,967.10x = 5,920,380,359.19
5. Step 5: Solve for x
   x = 5,920,380,359.19/64,967.10
6. Step 6: Final answer
   x = 91,128.90