Finding the Third Proportional to 286,034 and 428,499

Step by Step Solution

1. Step 1: Write the proportion equation
   286,034 : 428,499 = 428,499 : x
2. Step 2: Convert to fraction form
   286,034/428,499 = 428,499/x
3. Step 3: Cross multiply
   286,034x = 428,499 × 428,499
4. Step 4: Simplify right side
   286,034x = 183,611,393,001
5. Step 5: Solve for x
   x = 183,611,393,001/286,034
6. Step 6: Final answer
   x = 641,921.57