Finding the Third Proportional to 688.38 and 986.50

Step by Step Solution

1. Step 1: Write the proportion equation
   688.38 : 986.50 = 986.50 : x
2. Step 2: Convert to fraction form
   688.38/986.50 = 986.50/x
3. Step 3: Cross multiply
   688.38x = 986.50 × 986.50
4. Step 4: Simplify right side
   688.38x = 973,182.25
5. Step 5: Solve for x
   x = 973,182.25/688.38
6. Step 6: Final answer
   x = 1,413.74