Finding the Third Proportional to 21,570 and 28,990

Step by Step Solution

1. Step 1: Write the proportion equation
   21,570 : 28,990 = 28,990 : x
2. Step 2: Convert to fraction form
   21,570/28,990 = 28,990/x
3. Step 3: Cross multiply
   21,570x = 28,990 × 28,990
4. Step 4: Simplify right side
   21,570x = 840,420,100
5. Step 5: Solve for x
   x = 840,420,100/21,570
6. Step 6: Final answer
   x = 38,962.45