Home / 720-1,380

Finding the Third Proportional to 720 and 1,380

Calculator

Solution

The third proportional to 720 and 1,380 is: 2,645

Step by Step Solution

  1. Step 1: Write the proportion equation
    720 : 1,380 = 1,380 : x
  2. Step 2: Convert to fraction form
    720/1,380 = 1,380/x
  3. Step 3: Cross multiply
    720x = 1,380 × 1,380
  4. Step 4: Simplify right side
    720x = 1,904,400
  5. Step 5: Solve for x
    x = 1,904,400/720
  6. Step 6: Final answer
    x = 2,645

Related Problems

Find third proportional to 360 and 690
Half scale
Find third proportional to 1,440 and 2,760
Double scale
Find third proportional to 722 and 1,384
Similar ratio
Find third proportional to 1,080 and 2,070
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.92) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.