Finding the Third Proportional to 100,638 and 205,645.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100,638 : 205,645.50 = 205,645.50 : x
2. Step 2: Convert to fraction form
   100,638/205,645.50 = 205,645.50/x
3. Step 3: Cross multiply
   100,638x = 205,645.50 × 205,645.50
4. Step 4: Simplify right side
   100,638x = 42,290,071,670.25
5. Step 5: Solve for x
   x = 42,290,071,670.25/100,638
6. Step 6: Final answer
   x = 420,219.71