Finding the Third Proportional to 678.69 and 1,434.27

Step by Step Solution

1. Step 1: Write the proportion equation
   678.69 : 1,434.27 = 1,434.27 : x
2. Step 2: Convert to fraction form
   678.69/1,434.27 = 1,434.27/x
3. Step 3: Cross multiply
   678.69x = 1,434.27 × 1,434.27
4. Step 4: Simplify right side
   678.69x = 2,057,129.09
5. Step 5: Solve for x
   x = 2,057,129.09/678.69
6. Step 6: Final answer
   x = 3,031.02