Finding the Third Proportional to 116,978 and 256,212

Step by Step Solution

1. Step 1: Write the proportion equation
   116,978 : 256,212 = 256,212 : x
2. Step 2: Convert to fraction form
   116,978/256,212 = 256,212/x
3. Step 3: Cross multiply
   116,978x = 256,212 × 256,212
4. Step 4: Simplify right side
   116,978x = 65,644,588,944
5. Step 5: Solve for x
   x = 65,644,588,944/116,978
6. Step 6: Final answer
   x = 561,170.38