Finding the Third Proportional to 1,280 and 1,920

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280 : 1,920 = 1,920 : x
2. Step 2: Convert to fraction form
   1,280/1,920 = 1,920/x
3. Step 3: Cross multiply
   1,280x = 1,920 × 1,920
4. Step 4: Simplify right side
   1,280x = 3,686,400
5. Step 5: Solve for x
   x = 3,686,400/1,280
6. Step 6: Final answer
   x = 2,880