Home / 10-30

Finding the Third Proportional to 10 and 30

Calculator

Solution

The third proportional to 10 and 30 is: 90

Step by Step Solution

  1. Step 1: Write the proportion equation
    10 : 30 = 30 : x
  2. Step 2: Convert to fraction form
    10/30 = 30/x
  3. Step 3: Cross multiply
    10x = 30 × 30
  4. Step 4: Simplify right side
    10x = 900
  5. Step 5: Solve for x
    x = 900/10
  6. Step 6: Final answer
    x = 90

Related Problems

Find third proportional to 5 and 15
Half scale
Find third proportional to 20 and 60
Double scale
Find third proportional to 12 and 36
Similar ratio
Find third proportional to 15 and 45
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (3) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.