Home / 153-321

Finding the Third Proportional to 153 and 321

Calculator

Solution

The third proportional to 153 and 321 is: 673.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    153 : 321 = 321 : x
  2. Step 2: Convert to fraction form
    153/321 = 321/x
  3. Step 3: Cross multiply
    153x = 321 × 321
  4. Step 4: Simplify right side
    153x = 103,041
  5. Step 5: Solve for x
    x = 103,041/153
  6. Step 6: Final answer
    x = 673.47

Related Problems

Find third proportional to 76.50 and 160.50
Half scale
Find third proportional to 306 and 642
Double scale
Find third proportional to 155 and 325
Similar ratio
Find third proportional to 229.50 and 481.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.