Finding the Third Proportional to 721.25 and 1,665.50

Step by Step Solution

1. Step 1: Write the proportion equation
   721.25 : 1,665.50 = 1,665.50 : x
2. Step 2: Convert to fraction form
   721.25/1,665.50 = 1,665.50/x
3. Step 3: Cross multiply
   721.25x = 1,665.50 × 1,665.50
4. Step 4: Simplify right side
   721.25x = 2,773,890.25
5. Step 5: Solve for x
   x = 2,773,890.25/721.25
6. Step 6: Final answer
   x = 3,845.95