Finding the Third Proportional to 61,290 and 128,776.50

Step by Step Solution

1. Step 1: Write the proportion equation
   61,290 : 128,776.50 = 128,776.50 : x
2. Step 2: Convert to fraction form
   61,290/128,776.50 = 128,776.50/x
3. Step 3: Cross multiply
   61,290x = 128,776.50 × 128,776.50
4. Step 4: Simplify right side
   61,290x = 16,583,386,952.25
5. Step 5: Solve for x
   x = 16,583,386,952.25/61,290
6. Step 6: Final answer
   x = 270,572.47