Finding the Third Proportional to 139,469 and 286,290

Step by Step Solution

1. Step 1: Write the proportion equation
   139,469 : 286,290 = 286,290 : x
2. Step 2: Convert to fraction form
   139,469/286,290 = 286,290/x
3. Step 3: Cross multiply
   139,469x = 286,290 × 286,290
4. Step 4: Simplify right side
   139,469x = 81,961,964,100
5. Step 5: Solve for x
   x = 81,961,964,100/139,469
6. Step 6: Final answer
   x = 587,671.55