Finding the Third Proportional to 31,385 and 68,990

Step by Step Solution

1. Step 1: Write the proportion equation
   31,385 : 68,990 = 68,990 : x
2. Step 2: Convert to fraction form
   31,385/68,990 = 68,990/x
3. Step 3: Cross multiply
   31,385x = 68,990 × 68,990
4. Step 4: Simplify right side
   31,385x = 4,759,620,100
5. Step 5: Solve for x
   x = 4,759,620,100/31,385
6. Step 6: Final answer
   x = 151,652.70