Finding the Third Proportional to 21,218 and 31,820

Step by Step Solution

1. Step 1: Write the proportion equation
   21,218 : 31,820 = 31,820 : x
2. Step 2: Convert to fraction form
   21,218/31,820 = 31,820/x
3. Step 3: Cross multiply
   21,218x = 31,820 × 31,820
4. Step 4: Simplify right side
   21,218x = 1,012,512,400
5. Step 5: Solve for x
   x = 1,012,512,400/21,218
6. Step 6: Final answer
   x = 47,719.50