Finding the Third Proportional to 6,405 and 8,485.50

Step by Step Solution

1. Step 1: Write the proportion equation
   6,405 : 8,485.50 = 8,485.50 : x
2. Step 2: Convert to fraction form
   6,405/8,485.50 = 8,485.50/x
3. Step 3: Cross multiply
   6,405x = 8,485.50 × 8,485.50
4. Step 4: Simplify right side
   6,405x = 72,003,710.25
5. Step 5: Solve for x
   x = 72,003,710.25/6,405
6. Step 6: Final answer
   x = 11,241.80