Finding the Third Proportional to 189,388 and 405,042

Step by Step Solution

1. Step 1: Write the proportion equation
   189,388 : 405,042 = 405,042 : x
2. Step 2: Convert to fraction form
   189,388/405,042 = 405,042/x
3. Step 3: Cross multiply
   189,388x = 405,042 × 405,042
4. Step 4: Simplify right side
   189,388x = 164,059,021,764
5. Step 5: Solve for x
   x = 164,059,021,764/189,388
6. Step 6: Final answer
   x = 866,258.80