Finding the Third Proportional to 31,978 and 74,688

Step by Step Solution

1. Step 1: Write the proportion equation
   31,978 : 74,688 = 74,688 : x
2. Step 2: Convert to fraction form
   31,978/74,688 = 74,688/x
3. Step 3: Cross multiply
   31,978x = 74,688 × 74,688
4. Step 4: Simplify right side
   31,978x = 5,578,297,344
5. Step 5: Solve for x
   x = 5,578,297,344/31,978
6. Step 6: Final answer
   x = 174,441.72