Finding the Third Proportional to 128,763 and 200,422.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,763 : 200,422.50 = 200,422.50 : x
2. Step 2: Convert to fraction form
   128,763/200,422.50 = 200,422.50/x
3. Step 3: Cross multiply
   128,763x = 200,422.50 × 200,422.50
4. Step 4: Simplify right side
   128,763x = 40,169,178,506.25
5. Step 5: Solve for x
   x = 40,169,178,506.25/128,763
6. Step 6: Final answer
   x = 311,962.12