Finding the Third Proportional to 127,978 and 199,215

Step by Step Solution

1. Step 1: Write the proportion equation
   127,978 : 199,215 = 199,215 : x
2. Step 2: Convert to fraction form
   127,978/199,215 = 199,215/x
3. Step 3: Cross multiply
   127,978x = 199,215 × 199,215
4. Step 4: Simplify right side
   127,978x = 39,686,616,225
5. Step 5: Solve for x
   x = 39,686,616,225/127,978
6. Step 6: Final answer
   x = 310,104.99