Finding the Third Proportional to 811 and 1,662.50

Step by Step Solution

1. Step 1: Write the proportion equation
   811 : 1,662.50 = 1,662.50 : x
2. Step 2: Convert to fraction form
   811/1,662.50 = 1,662.50/x
3. Step 3: Cross multiply
   811x = 1,662.50 × 1,662.50
4. Step 4: Simplify right side
   811x = 2,763,906.25
5. Step 5: Solve for x
   x = 2,763,906.25/811
6. Step 6: Final answer
   x = 3,408.02