Finding the Third Proportional to 128,385 and 253,307.25

Step by Step Solution

1. Step 1: Write the proportion equation
   128,385 : 253,307.25 = 253,307.25 : x
2. Step 2: Convert to fraction form
   128,385/253,307.25 = 253,307.25/x
3. Step 3: Cross multiply
   128,385x = 253,307.25 × 253,307.25
4. Step 4: Simplify right side
   128,385x = 64,164,562,902.56
5. Step 5: Solve for x
   x = 64,164,562,902.56/128,385
6. Step 6: Final answer
   x = 499,782.40