Finding the Third Proportional to 642.94 and 979.59

Step by Step Solution

1. Step 1: Write the proportion equation
   642.94 : 979.59 = 979.59 : x
2. Step 2: Convert to fraction form
   642.94/979.59 = 979.59/x
3. Step 3: Cross multiply
   642.94x = 979.59 × 979.59
4. Step 4: Simplify right side
   642.94x = 959,603.92
5. Step 5: Solve for x
   x = 959,603.92/642.94
6. Step 6: Final answer
   x = 1,492.53