Finding the Third Proportional to 31,420 and 66,071.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,420 : 66,071.50 = 66,071.50 : x
2. Step 2: Convert to fraction form
   31,420/66,071.50 = 66,071.50/x
3. Step 3: Cross multiply
   31,420x = 66,071.50 × 66,071.50
4. Step 4: Simplify right side
   31,420x = 4,365,443,112.25
5. Step 5: Solve for x
   x = 4,365,443,112.25/31,420
6. Step 6: Final answer
   x = 138,938.35