Finding the Third Proportional to 393 and 1,057.50

Step by Step Solution

1. Step 1: Write the proportion equation
   393 : 1,057.50 = 1,057.50 : x
2. Step 2: Convert to fraction form
   393/1,057.50 = 1,057.50/x
3. Step 3: Cross multiply
   393x = 1,057.50 × 1,057.50
4. Step 4: Simplify right side
   393x = 1,118,306.25
5. Step 5: Solve for x
   x = 1,118,306.25/393
6. Step 6: Final answer
   x = 2,845.56