Home / 328-639

Finding the Third Proportional to 328 and 639

Calculator

Solution

The third proportional to 328 and 639 is: 1,244.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    328 : 639 = 639 : x
  2. Step 2: Convert to fraction form
    328/639 = 639/x
  3. Step 3: Cross multiply
    328x = 639 × 639
  4. Step 4: Simplify right side
    328x = 408,321
  5. Step 5: Solve for x
    x = 408,321/328
  6. Step 6: Final answer
    x = 1,244.88

Related Problems

Find third proportional to 164 and 319.50
Half scale
Find third proportional to 656 and 1,278
Double scale
Find third proportional to 330 and 643
Similar ratio
Find third proportional to 492 and 958.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.95) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.