Finding the Third Proportional to 355.78 and 765.42

Step by Step Solution

1. Step 1: Write the proportion equation
   355.78 : 765.42 = 765.42 : x
2. Step 2: Convert to fraction form
   355.78/765.42 = 765.42/x
3. Step 3: Cross multiply
   355.78x = 765.42 × 765.42
4. Step 4: Simplify right side
   355.78x = 585,870.65
5. Step 5: Solve for x
   x = 585,870.65/355.78
6. Step 6: Final answer
   x = 1,646.72