Finding the Third Proportional to 128,266.50 and 278,434

Step by Step Solution

1. Step 1: Write the proportion equation
   128,266.50 : 278,434 = 278,434 : x
2. Step 2: Convert to fraction form
   128,266.50/278,434 = 278,434/x
3. Step 3: Cross multiply
   128,266.50x = 278,434 × 278,434
4. Step 4: Simplify right side
   128,266.50x = 77,525,492,356
5. Step 5: Solve for x
   x = 77,525,492,356/128,266.50
6. Step 6: Final answer
   x = 604,409.51