Finding the Third Proportional to 3,991.50 and 8,181.75

Step by Step Solution

1. Step 1: Write the proportion equation
   3,991.50 : 8,181.75 = 8,181.75 : x
2. Step 2: Convert to fraction form
   3,991.50/8,181.75 = 8,181.75/x
3. Step 3: Cross multiply
   3,991.50x = 8,181.75 × 8,181.75
4. Step 4: Simplify right side
   3,991.50x = 66,941,033.06
5. Step 5: Solve for x
   x = 66,941,033.06/3,991.50
6. Step 6: Final answer
   x = 16,770.90