Home / 318-691

Finding the Third Proportional to 318 and 691

Calculator

Solution

The third proportional to 318 and 691 is: 1,501.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    318 : 691 = 691 : x
  2. Step 2: Convert to fraction form
    318/691 = 691/x
  3. Step 3: Cross multiply
    318x = 691 × 691
  4. Step 4: Simplify right side
    318x = 477,481
  5. Step 5: Solve for x
    x = 477,481/318
  6. Step 6: Final answer
    x = 1,501.51

Related Problems

Find third proportional to 159 and 345.50
Half scale
Find third proportional to 636 and 1,382
Double scale
Find third proportional to 320 and 695
Similar ratio
Find third proportional to 477 and 1,036.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.