Home / 643-817

Finding the Third Proportional to 643 and 817

Calculator

Solution

The third proportional to 643 and 817 is: 1,038.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    643 : 817 = 817 : x
  2. Step 2: Convert to fraction form
    643/817 = 817/x
  3. Step 3: Cross multiply
    643x = 817 × 817
  4. Step 4: Simplify right side
    643x = 667,489
  5. Step 5: Solve for x
    x = 667,489/643
  6. Step 6: Final answer
    x = 1,038.09

Related Problems

Find third proportional to 321.50 and 408.50
Half scale
Find third proportional to 1,286 and 1,634
Double scale
Find third proportional to 645 and 820
Similar ratio
Find third proportional to 964.50 and 1,225.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.27) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.