Home / 389-641

Finding the Third Proportional to 389 and 641

Calculator

Solution

The third proportional to 389 and 641 is: 1,056.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    389 : 641 = 641 : x
  2. Step 2: Convert to fraction form
    389/641 = 641/x
  3. Step 3: Cross multiply
    389x = 641 × 641
  4. Step 4: Simplify right side
    389x = 410,881
  5. Step 5: Solve for x
    x = 410,881/389
  6. Step 6: Final answer
    x = 1,056.25

Related Problems

Find third proportional to 194.50 and 320.50
Half scale
Find third proportional to 778 and 1,282
Double scale
Find third proportional to 391 and 644
Similar ratio
Find third proportional to 583.50 and 961.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.65) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.