Finding the Third Proportional to 1,218 and 1,980

Step by Step Solution

1. Step 1: Write the proportion equation
   1,218 : 1,980 = 1,980 : x
2. Step 2: Convert to fraction form
   1,218/1,980 = 1,980/x
3. Step 3: Cross multiply
   1,218x = 1,980 × 1,980
4. Step 4: Simplify right side
   1,218x = 3,920,400
5. Step 5: Solve for x
   x = 3,920,400/1,218
6. Step 6: Final answer
   x = 3,218.72