Finding the Third Proportional to 31,218 and 67,989

Step by Step Solution

1. Step 1: Write the proportion equation
   31,218 : 67,989 = 67,989 : x
2. Step 2: Convert to fraction form
   31,218/67,989 = 67,989/x
3. Step 3: Cross multiply
   31,218x = 67,989 × 67,989
4. Step 4: Simplify right side
   31,218x = 4,622,504,121
5. Step 5: Solve for x
   x = 4,622,504,121/31,218
6. Step 6: Final answer
   x = 148,071.76