Finding the Third Proportional to 28,440 and 42,660

Step by Step Solution

1. Step 1: Write the proportion equation
   28,440 : 42,660 = 42,660 : x
2. Step 2: Convert to fraction form
   28,440/42,660 = 42,660/x
3. Step 3: Cross multiply
   28,440x = 42,660 × 42,660
4. Step 4: Simplify right side
   28,440x = 1,819,875,600
5. Step 5: Solve for x
   x = 1,819,875,600/28,440
6. Step 6: Final answer
   x = 63,990