Finding the Third Proportional to 17,620 and 39,890

Step by Step Solution

1. Step 1: Write the proportion equation
   17,620 : 39,890 = 39,890 : x
2. Step 2: Convert to fraction form
   17,620/39,890 = 39,890/x
3. Step 3: Cross multiply
   17,620x = 39,890 × 39,890
4. Step 4: Simplify right side
   17,620x = 1,591,212,100
5. Step 5: Solve for x
   x = 1,591,212,100/17,620
6. Step 6: Final answer
   x = 90,307.16