Finding the Third Proportional to 191,921 and 405,986

Step by Step Solution

1. Step 1: Write the proportion equation
   191,921 : 405,986 = 405,986 : x
2. Step 2: Convert to fraction form
   191,921/405,986 = 405,986/x
3. Step 3: Cross multiply
   191,921x = 405,986 × 405,986
4. Step 4: Simplify right side
   191,921x = 164,824,632,196
5. Step 5: Solve for x
   x = 164,824,632,196/191,921
6. Step 6: Final answer
   x = 858,814.99