Finding the Third Proportional to 128,605.50 and 282,111.75

Step by Step Solution

1. Step 1: Write the proportion equation
   128,605.50 : 282,111.75 = 282,111.75 : x
2. Step 2: Convert to fraction form
   128,605.50/282,111.75 = 282,111.75/x
3. Step 3: Cross multiply
   128,605.50x = 282,111.75 × 282,111.75
4. Step 4: Simplify right side
   128,605.50x = 79,587,039,488.06
5. Step 5: Solve for x
   x = 79,587,039,488.06/128,605.50
6. Step 6: Final answer
   x = 618,846.31