Home / 728-1,380

Finding the Third Proportional to 728 and 1,380

Calculator

Solution

The third proportional to 728 and 1,380 is: 2,615.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    728 : 1,380 = 1,380 : x
  2. Step 2: Convert to fraction form
    728/1,380 = 1,380/x
  3. Step 3: Cross multiply
    728x = 1,380 × 1,380
  4. Step 4: Simplify right side
    728x = 1,904,400
  5. Step 5: Solve for x
    x = 1,904,400/728
  6. Step 6: Final answer
    x = 2,615.93

Related Problems

Find third proportional to 364 and 690
Half scale
Find third proportional to 1,456 and 2,760
Double scale
Find third proportional to 730 and 1,384
Similar ratio
Find third proportional to 1,092 and 2,070
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.90) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.