Finding the Third Proportional to 199,978.50 and 281,256

Step by Step Solution

1. Step 1: Write the proportion equation
   199,978.50 : 281,256 = 281,256 : x
2. Step 2: Convert to fraction form
   199,978.50/281,256 = 281,256/x
3. Step 3: Cross multiply
   199,978.50x = 281,256 × 281,256
4. Step 4: Simplify right side
   199,978.50x = 79,104,937,536
5. Step 5: Solve for x
   x = 79,104,937,536/199,978.50
6. Step 6: Final answer
   x = 395,567.21