Home / 440-688

Finding the Third Proportional to 440 and 688

Calculator

Solution

The third proportional to 440 and 688 is: 1,075.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    440 : 688 = 688 : x
  2. Step 2: Convert to fraction form
    440/688 = 688/x
  3. Step 3: Cross multiply
    440x = 688 × 688
  4. Step 4: Simplify right side
    440x = 473,344
  5. Step 5: Solve for x
    x = 473,344/440
  6. Step 6: Final answer
    x = 1,075.78

Related Problems

Find third proportional to 220 and 344
Half scale
Find third proportional to 880 and 1,376
Double scale
Find third proportional to 442 and 691
Similar ratio
Find third proportional to 660 and 1,032
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.