Finding the Third Proportional to 64,206 and 72,409.50

Step by Step Solution

1. Step 1: Write the proportion equation
   64,206 : 72,409.50 = 72,409.50 : x
2. Step 2: Convert to fraction form
   64,206/72,409.50 = 72,409.50/x
3. Step 3: Cross multiply
   64,206x = 72,409.50 × 72,409.50
4. Step 4: Simplify right side
   64,206x = 5,243,135,690.25
5. Step 5: Solve for x
   x = 5,243,135,690.25/64,206
6. Step 6: Final answer
   x = 81,661.15