Finding the Third Proportional to 646.50 and 989.25

Step by Step Solution

1. Step 1: Write the proportion equation
   646.50 : 989.25 = 989.25 : x
2. Step 2: Convert to fraction form
   646.50/989.25 = 989.25/x
3. Step 3: Cross multiply
   646.50x = 989.25 × 989.25
4. Step 4: Simplify right side
   646.50x = 978,615.56
5. Step 5: Solve for x
   x = 978,615.56/646.50
6. Step 6: Final answer
   x = 1,513.71