Finding the Third Proportional to 196,890 and 421,660.50

Step by Step Solution

1. Step 1: Write the proportion equation
   196,890 : 421,660.50 = 421,660.50 : x
2. Step 2: Convert to fraction form
   196,890/421,660.50 = 421,660.50/x
3. Step 3: Cross multiply
   196,890x = 421,660.50 × 421,660.50
4. Step 4: Simplify right side
   196,890x = 177,797,577,260.25
5. Step 5: Solve for x
   x = 177,797,577,260.25/196,890
6. Step 6: Final answer
   x = 903,030.00