Finding the Third Proportional to 77,638.50 and 138,646.69

Step by Step Solution

1. Step 1: Write the proportion equation
   77,638.50 : 138,646.69 = 138,646.69 : x
2. Step 2: Convert to fraction form
   77,638.50/138,646.69 = 138,646.69/x
3. Step 3: Cross multiply
   77,638.50x = 138,646.69 × 138,646.69
4. Step 4: Simplify right side
   77,638.50x = 19,222,903,954.72
5. Step 5: Solve for x
   x = 19,222,903,954.72/77,638.50
6. Step 6: Final answer
   x = 247,594.99