Finding the Third Proportional to 31,099.78 and 66,636.56

Step by Step Solution

1. Step 1: Write the proportion equation
   31,099.78 : 66,636.56 = 66,636.56 : x
2. Step 2: Convert to fraction form
   31,099.78/66,636.56 = 66,636.56/x
3. Step 3: Cross multiply
   31,099.78x = 66,636.56 × 66,636.56
4. Step 4: Simplify right side
   31,099.78x = 4,440,431,461.82
5. Step 5: Solve for x
   x = 4,440,431,461.82/31,099.78
6. Step 6: Final answer
   x = 142,780.15