Finding the Third Proportional to 291,927 and 439,978

Step by Step Solution

1. Step 1: Write the proportion equation
   291,927 : 439,978 = 439,978 : x
2. Step 2: Convert to fraction form
   291,927/439,978 = 439,978/x
3. Step 3: Cross multiply
   291,927x = 439,978 × 439,978
4. Step 4: Simplify right side
   291,927x = 193,580,640,484
5. Step 5: Solve for x
   x = 193,580,640,484/291,927
6. Step 6: Final answer
   x = 663,113.18