Finding the Third Proportional to 274.69 and 431.69

Step by Step Solution

1. Step 1: Write the proportion equation
   274.69 : 431.69 = 431.69 : x
2. Step 2: Convert to fraction form
   274.69/431.69 = 431.69/x
3. Step 3: Cross multiply
   274.69x = 431.69 × 431.69
4. Step 4: Simplify right side
   274.69x = 186,354.10
5. Step 5: Solve for x
   x = 186,354.10/274.69
6. Step 6: Final answer
   x = 678.42