Finding the Third Proportional to 128,830.50 and 189,000

Step by Step Solution

1. Step 1: Write the proportion equation
   128,830.50 : 189,000 = 189,000 : x
2. Step 2: Convert to fraction form
   128,830.50/189,000 = 189,000/x
3. Step 3: Cross multiply
   128,830.50x = 189,000 × 189,000
4. Step 4: Simplify right side
   128,830.50x = 35,721,000,000
5. Step 5: Solve for x
   x = 35,721,000,000/128,830.50
6. Step 6: Final answer
   x = 277,271.30