Finding the Third Proportional to 111,919.50 and 275,971.50

Step by Step Solution

1. Step 1: Write the proportion equation
   111,919.50 : 275,971.50 = 275,971.50 : x
2. Step 2: Convert to fraction form
   111,919.50/275,971.50 = 275,971.50/x
3. Step 3: Cross multiply
   111,919.50x = 275,971.50 × 275,971.50
4. Step 4: Simplify right side
   111,919.50x = 76,160,268,812.25
5. Step 5: Solve for x
   x = 76,160,268,812.25/111,919.50
6. Step 6: Final answer
   x = 680,491.50