Finding the Third Proportional to 4,912 and 7,870

Step by Step Solution

1. Step 1: Write the proportion equation
   4,912 : 7,870 = 7,870 : x
2. Step 2: Convert to fraction form
   4,912/7,870 = 7,870/x
3. Step 3: Cross multiply
   4,912x = 7,870 × 7,870
4. Step 4: Simplify right side
   4,912x = 61,936,900
5. Step 5: Solve for x
   x = 61,936,900/4,912
6. Step 6: Final answer
   x = 12,609.30