Finding the Third Proportional to 7,980 and 12,630.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,980 : 12,630.50 = 12,630.50 : x
2. Step 2: Convert to fraction form
   7,980/12,630.50 = 12,630.50/x
3. Step 3: Cross multiply
   7,980x = 12,630.50 × 12,630.50
4. Step 4: Simplify right side
   7,980x = 159,529,530.25
5. Step 5: Solve for x
   x = 159,529,530.25/7,980
6. Step 6: Final answer
   x = 19,991.17