Finding the Third Proportional to 128,130 and 200,419.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,130 : 200,419.50 = 200,419.50 : x
2. Step 2: Convert to fraction form
   128,130/200,419.50 = 200,419.50/x
3. Step 3: Cross multiply
   128,130x = 200,419.50 × 200,419.50
4. Step 4: Simplify right side
   128,130x = 40,167,975,980.25
5. Step 5: Solve for x
   x = 40,167,975,980.25/128,130
6. Step 6: Final answer
   x = 313,493.92