Finding the Third Proportional to 31,980 and 51,090

Step by Step Solution

1. Step 1: Write the proportion equation
   31,980 : 51,090 = 51,090 : x
2. Step 2: Convert to fraction form
   31,980/51,090 = 51,090/x
3. Step 3: Cross multiply
   31,980x = 51,090 × 51,090
4. Step 4: Simplify right side
   31,980x = 2,610,188,100
5. Step 5: Solve for x
   x = 2,610,188,100/31,980
6. Step 6: Final answer
   x = 81,619.39