Finding the Third Proportional to 820.50 and 1,980

Step by Step Solution

1. Step 1: Write the proportion equation
   820.50 : 1,980 = 1,980 : x
2. Step 2: Convert to fraction form
   820.50/1,980 = 1,980/x
3. Step 3: Cross multiply
   820.50x = 1,980 × 1,980
4. Step 4: Simplify right side
   820.50x = 3,920,400
5. Step 5: Solve for x
   x = 3,920,400/820.50
6. Step 6: Final answer
   x = 4,778.06