Home / 571-639

Finding the Third Proportional to 571 and 639

Calculator

Solution

The third proportional to 571 and 639 is: 715.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    571 : 639 = 639 : x
  2. Step 2: Convert to fraction form
    571/639 = 639/x
  3. Step 3: Cross multiply
    571x = 639 × 639
  4. Step 4: Simplify right side
    571x = 408,321
  5. Step 5: Solve for x
    x = 408,321/571
  6. Step 6: Final answer
    x = 715.10

Related Problems

Find third proportional to 285.50 and 319.50
Half scale
Find third proportional to 1,142 and 1,278
Double scale
Find third proportional to 573 and 641
Similar ratio
Find third proportional to 856.50 and 958.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.12) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.