Finding the Third Proportional to 100,978.50 and 212,403

Step by Step Solution

1. Step 1: Write the proportion equation
   100,978.50 : 212,403 = 212,403 : x
2. Step 2: Convert to fraction form
   100,978.50/212,403 = 212,403/x
3. Step 3: Cross multiply
   100,978.50x = 212,403 × 212,403
4. Step 4: Simplify right side
   100,978.50x = 45,115,034,409
5. Step 5: Solve for x
   x = 45,115,034,409/100,978.50
6. Step 6: Final answer
   x = 446,778.62