Finding the Third Proportional to 200,870 and 311,290

Step by Step Solution

1. Step 1: Write the proportion equation
   200,870 : 311,290 = 311,290 : x
2. Step 2: Convert to fraction form
   200,870/311,290 = 311,290/x
3. Step 3: Cross multiply
   200,870x = 311,290 × 311,290
4. Step 4: Simplify right side
   200,870x = 96,901,464,100
5. Step 5: Solve for x
   x = 96,901,464,100/200,870
6. Step 6: Final answer
   x = 482,408.84