Finding the Third Proportional to 623.50 and 679.50

Step by Step Solution

1. Step 1: Write the proportion equation
   623.50 : 679.50 = 679.50 : x
2. Step 2: Convert to fraction form
   623.50/679.50 = 679.50/x
3. Step 3: Cross multiply
   623.50x = 679.50 × 679.50
4. Step 4: Simplify right side
   623.50x = 461,720.25
5. Step 5: Solve for x
   x = 461,720.25/623.50
6. Step 6: Final answer
   x = 740.53