Finding the Third Proportional to 663.19 and 1,428.89

Step by Step Solution

1. Step 1: Write the proportion equation
   663.19 : 1,428.89 = 1,428.89 : x
2. Step 2: Convert to fraction form
   663.19/1,428.89 = 1,428.89/x
3. Step 3: Cross multiply
   663.19x = 1,428.89 × 1,428.89
4. Step 4: Simplify right side
   663.19x = 2,041,728.42
5. Step 5: Solve for x
   x = 2,041,728.42/663.19
6. Step 6: Final answer
   x = 3,078.66