Finding the Third Proportional to 189,931.50 and 405,288

Step by Step Solution

1. Step 1: Write the proportion equation
   189,931.50 : 405,288 = 405,288 : x
2. Step 2: Convert to fraction form
   189,931.50/405,288 = 405,288/x
3. Step 3: Cross multiply
   189,931.50x = 405,288 × 405,288
4. Step 4: Simplify right side
   189,931.50x = 164,258,362,944
5. Step 5: Solve for x
   x = 164,258,362,944/189,931.50
6. Step 6: Final answer
   x = 864,829.49