Finding the Fourth Proportional to 64,912.70, 91,009 and 64,912.70

Step by Step Solution

1. Step 1: Write the proportion equation
   64,912.70 : 91,009 = 64,912.70 : x
2. Step 2: Convert to fraction form
   64,912.70/91,009 = 64,912.70/x
3. Step 3: Cross multiply
   64,912.70x = 91,009 × 64,912.70
4. Step 4: Simplify right side
   64,912.70x = 5,907,639,914.30
5. Step 5: Solve for x
   x = 5,907,639,914.30/64,912.70
6. Step 6: Final answer
   x = 91,009