Home / 7.21-11.21

Finding the Third Proportional to 7.21 and 11.21

Calculator

Solution

The third proportional to 7.21 and 11.21 is: 17.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.21 : 11.21 = 11.21 : x
  2. Step 2: Convert to fraction form
    7.21/11.21 = 11.21/x
  3. Step 3: Cross multiply
    7.21x = 11.21 × 11.21
  4. Step 4: Simplify right side
    7.21x = 125.72
  5. Step 5: Solve for x
    x = 125.72/7.21
  6. Step 6: Final answer
    x = 17.44

Related Problems

Find third proportional to 3.60 and 5.61
Half scale
Find third proportional to 14.42 and 22.43
Double scale
Find third proportional to 9 and 14
Similar ratio
Find third proportional to 10.81 and 16.82
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.