Home / 422.81-640.69

Finding the Third Proportional to 422.81 and 640.69

Calculator

Solution

The third proportional to 422.81 and 640.69 is: 970.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.81 : 640.69 = 640.69 : x
  2. Step 2: Convert to fraction form
    422.81/640.69 = 640.69/x
  3. Step 3: Cross multiply
    422.81x = 640.69 × 640.69
  4. Step 4: Simplify right side
    422.81x = 410,480.47
  5. Step 5: Solve for x
    x = 410,480.47/422.81
  6. Step 6: Final answer
    x = 970.83

Related Problems

Find third proportional to 211.41 and 320.34
Half scale
Find third proportional to 845.63 and 1,281.38
Double scale
Find third proportional to 425 and 644
Similar ratio
Find third proportional to 634.22 and 961.03
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.52) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.