Finding the Third Proportional to 21,490 and 31,830

Step by Step Solution

1. Step 1: Write the proportion equation
   21,490 : 31,830 = 31,830 : x
2. Step 2: Convert to fraction form
   21,490/31,830 = 31,830/x
3. Step 3: Cross multiply
   21,490x = 31,830 × 31,830
4. Step 4: Simplify right side
   21,490x = 1,013,148,900
5. Step 5: Solve for x
   x = 1,013,148,900/21,490
6. Step 6: Final answer
   x = 47,145.13